diff mbox series

mmc: sd: Remove the patch that fix signal voltage when there is no power cycle

Message ID 20220721055924.9043-1-sh043.lee@samsung.com
State New
Headers show
Series mmc: sd: Remove the patch that fix signal voltage when there is no power cycle | expand

Commit Message

이승희 July 21, 2022, 5:59 a.m. UTC
At first, all error flow of mmc_set_uhs_voltage() has power cycle
except R1_ERROR and no start_signal_voltage_switch() func pointer.

There is the performance regression issue of SDR104 SD card from
the market VOC. Normally, once a SDR104 SD card fails to switch voltage,
it works HS mode.
And then it initializes SDR104 mode after system resume or error handling.

However, with below patch,
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/drivers/mmc/core/sd.c?id=6a11fc47f175c8d87018e89cb58e2d36c66534cb
Once a SD card does, it initializes SDR25 mode forever
after system resume or error handling(re-initialized).
Host updates sd3_bus_mode by calling mmc_read_switch(),
the value of sd3_bus_mode doesn't set for SDR104, SDR50 and DDR50 mode.

So, if host doesn't update sd3_bus_mode,
the SD card works SDR104 mode after system resume or error-handling.

Here is an example.

AS-IS : test log
// normal case : sd3_bus_mode = 0x1F, sd_bus_speed = SDR104, clock 208MHz
[  111.907789] [1:    kworker/1:3:  772] [TEST] mmc_sd_init_card: 1119: caps=0x407f020f, sd3_bus_mode=0x1f, v18_fixup_failed false, signal_voltage =0x1.
[  111.907824] [1:    kworker/1:3:  772] [TEST] mmc_sd_init_card: 1149: rocr 0xc1ff8000, S18A, uhs.
[  111.908707] [1:    kworker/1:3:  772] [TEST] sd_update_bus_speed_mode: caps 0x407f020f, sd3_bus_mode = 0x1f, sd_bus_speed = 3, card->ocr = 0x40000.
[  111.912484] [1:    kworker/1:3:  772] [TEST] sd_set_bus_speed_mode: sd_bus_speed=3, timing=6, uhs_max_dtr=208000000, card->ocr=0x40000.
// resume : issue occurs : SDcard doesn't release busy for checking 10 times
[  112.096550] [5:    kworker/5:2:  207] [TEST] mmc_sd_init_card: 1040: card->ocr 0x40000.
[  112.096560] [5:    kworker/5:2:  207] [TEST] mmc_sd_get_cid: ocr 0x40000(pocr 0x40000), retries 10.
...
[  114.531129] [5:    kworker/5:2:  207] [TEST] mmc_power_cycle.
[  114.579500] [5:    kworker/5:2:  207] [TEST] mmc_sd_get_cid: ocr 0x41040000(pocr 0x40000), retries 0.
[  114.579506] [5:    kworker/5:2:  207] mmc0: Skipping voltage switch
[  114.757575] [5:    kworker/5:2:  207] [TEST] mmc_sd_init_card: 1119: caps=0x407f020f, sd3_bus_mode=0x1f, v18_fixup_failed false, signal_voltage =0x0.
[  114.757583] [5:    kworker/5:2:  207] [TEST] mmc_sd_init_card: 1128: switch with oldcard.
[  114.759742] [5:    kworker/5:2:  207] [TEST] mmc_read_switch: sd_switch ret 0, sd3_bus_mode=3.
// sd3_bus_mode = 0x3 supports HS, SDR25 and SDR12
[  114.759750] [5:    kworker/5:2:  207] [TEST] mmc_sd_init_card: 1157: switch hs.
// next resume : the SDcard initializes to SDR25(HS) mode(sd_bus_speed = 1) by sd3_bus_mode setting with clk 50MHz
[  114.968346] [5:    kworker/5:2:  207] [TEST] mmc_sd_init_card: 1040: card->ocr 0x40000.
[  114.968359] [5:    kworker/5:2:  207] [TEST] mmc_sd_get_cid: ocr 0x40000(pocr 0x40000), retries 10.
[  115.167346] [5:    kworker/5:2:  207] [TEST] mmc_sd_init_card: 1119: caps=0x407f020f, sd3_bus_mode=0x3, v18_fixup_failed false, signal_voltage =0x1.
[  115.167366] [5:    kworker/5:2:  207] [TEST] mmc_sd_init_card: 1149: rocr 0xc1ff8000, S18A, uhs.
[  115.168041] [5:    kworker/5:2:  207] [TEST] mmc_sd_init_uhs_card: before update: caps 0x407f020f, sd3_bus_mode = 3, sd_bus_speed = 3, card->ocr = 0x40000.
[  115.168051] [5:    kworker/5:2:  207] [TEST] sd_update_bus_speed_mode: caps 0x407f020f, sd3_bus_mode = 3, sd_bus_speed = 1, card->ocr = 0x40000.
[  115.169176] [5:    kworker/5:2:  207] [TEST] sd_set_bus_speed_mode: sd_bus_speed=1, timing=4, uhs_max_dtr=50000000, card->ocr=0x40000.

TO-BE : TEST log with this commit
// resume : issue occurs : SDcard doesn't release busy for checking 10 times
[ 1843.594805] [4:    kworker/4:5:21512] [TEST] mmc_sd_get_cid: ocr 0x41040000(pocr 0x40000), retries 0.
[ 1843.594812] [4:    kworker/4:5:21512] mmc0: Skipping voltage switch
[ 1843.772555] [4:    kworker/4:5:21512] [TEST] mmc_sd_init_card: 1122: caps=0x407f020f, sd3_bus_mode=0x1f, v18_fixup_failed false, signal_voltage =0x0.
// no update sd3_bus_mode value
[ 1843.772563] [4:    kworker/4:5:21512] [TEST] mmc_sd_init_card: 1164: switch hs.
// next resume : the SDcard initializes to SDR104
[ 1844.191295] [5:   kworker/5:93: 2282] [TEST] mmc_sd_init_card: 1122: caps=0x407f020f, sd3_bus_mode=0x1f, v18_fixup_failed false, signal_voltage =0x1.
[ 1844.191315] [5:   kworker/5:93: 2282] [TEST] mmc_sd_init_card: 1154: rocr 0xc1ff8000, S18A, uhs.
[ 1844.192175] [5:   kworker/5:93: 2282] [TEST] mmc_sd_init_uhs_card: before update: caps 0x407f020f, sd3_bus_mode = 0x1f, sd_bus_speed = 3, card->ocr = 0x40000.
[ 1844.192187] [5:   kworker/5:93: 2282] [TEST] sd_update_bus_speed_mode: caps 0x407f020f, sd3_bus_mode = 0x1f, sd_bus_speed = 3, card->ocr = 0x40000.
[ 1844.198697] [5:   kworker/5:93: 2282] [TEST] sd_set_bus_speed_mode: sd_bus_speed=3, timing=6, uhs_max_dtr=208000000, card->ocr=0x40000.

Signed-off-by: Seunghui Lee <sh043.lee@samsung.com>
Tested-by: DooHyun Hwang <dh0421.hwang@samsung.com>
---
 drivers/mmc/core/sd.c | 47 ++-----------------------------------------
 1 file changed, 2 insertions(+), 45 deletions(-)

Comments

이승희 July 26, 2022, 2:56 a.m. UTC | #1
> -----Original Message-----
> From: Seunghui Lee <sh043.lee@samsung.com>
> Sent: Thursday, July 21, 2022 2:59 PM
> To: ulf.hansson@linaro.org; linux-mmc@vger.kernel.org;
> adrian.hunter@intel.com
> Cc: Seunghui Lee <sh043.lee@samsung.com>; DooHyun Hwang
> <dh0421.hwang@samsung.com>
> Subject: [PATCH] mmc: sd: Remove the patch that fix signal voltage when
> there is no power cycle
> 
> At first, all error flow of mmc_set_uhs_voltage() has power cycle except
> R1_ERROR and no start_signal_voltage_switch() func pointer.
> 
> There is the performance regression issue of SDR104 SD card from the
> market VOC. Normally, once a SDR104 SD card fails to switch voltage, it
> works HS mode.
> And then it initializes SDR104 mode after system resume or error handling.
> 
> However, with below patch,
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/
> drivers/mmc/core/sd.c?id=6a11fc47f175c8d87018e89cb58e2d36c66534cb
> Once a SD card does, it initializes SDR25 mode forever after system resume
> or error handling(re-initialized).
> Host updates sd3_bus_mode by calling mmc_read_switch(), the value of
> sd3_bus_mode doesn't set for SDR104, SDR50 and DDR50 mode.
> 
> So, if host doesn't update sd3_bus_mode, the SD card works SDR104 mode
> after system resume or error-handling.
> 
> Here is an example.
> 
> AS-IS : test log
> // normal case : sd3_bus_mode = 0x1F, sd_bus_speed = SDR104, clock 208MHz
> [  111.907789] [1:    kworker/1:3:  772] [TEST] mmc_sd_init_card: 1119:
> caps=0x407f020f, sd3_bus_mode=0x1f, v18_fixup_failed false, signal_voltage
> =0x1.
> [  111.907824] [1:    kworker/1:3:  772] [TEST] mmc_sd_init_card: 1149: rocr
> 0xc1ff8000, S18A, uhs.
> [  111.908707] [1:    kworker/1:3:  772] [TEST] sd_update_bus_speed_mode:
> caps 0x407f020f, sd3_bus_mode = 0x1f, sd_bus_speed = 3, card->ocr =
> 0x40000.
> [  111.912484] [1:    kworker/1:3:  772] [TEST] sd_set_bus_speed_mode:
> sd_bus_speed=3, timing=6, uhs_max_dtr=208000000, card->ocr=0x40000.
> // resume : issue occurs : SDcard doesn't release busy for checking 10
> times
> [  112.096550] [5:    kworker/5:2:  207] [TEST] mmc_sd_init_card: 1040:
> card->ocr 0x40000.
> [  112.096560] [5:    kworker/5:2:  207] [TEST] mmc_sd_get_cid: ocr
> 0x40000(pocr 0x40000), retries 10.
> ...
> [  114.531129] [5:    kworker/5:2:  207] [TEST] mmc_power_cycle.
> [  114.579500] [5:    kworker/5:2:  207] [TEST] mmc_sd_get_cid: ocr
> 0x41040000(pocr 0x40000), retries 0.
> [  114.579506] [5:    kworker/5:2:  207] mmc0: Skipping voltage switch
> [  114.757575] [5:    kworker/5:2:  207] [TEST] mmc_sd_init_card: 1119:
> caps=0x407f020f, sd3_bus_mode=0x1f, v18_fixup_failed false, signal_voltage
> =0x0.
> [  114.757583] [5:    kworker/5:2:  207] [TEST] mmc_sd_init_card: 1128:
> switch with oldcard.
> [  114.759742] [5:    kworker/5:2:  207] [TEST] mmc_read_switch: sd_switch
> ret 0, sd3_bus_mode=3.
> // sd3_bus_mode = 0x3 supports HS, SDR25 and SDR12
> [  114.759750] [5:    kworker/5:2:  207] [TEST] mmc_sd_init_card: 1157:
> switch hs.
> // next resume : the SDcard initializes to SDR25(HS) mode(sd_bus_speed = 1)
> by sd3_bus_mode setting with clk 50MHz
> [  114.968346] [5:    kworker/5:2:  207] [TEST] mmc_sd_init_card: 1040:
> card->ocr 0x40000.
> [  114.968359] [5:    kworker/5:2:  207] [TEST] mmc_sd_get_cid: ocr
> 0x40000(pocr 0x40000), retries 10.
> [  115.167346] [5:    kworker/5:2:  207] [TEST] mmc_sd_init_card: 1119:
> caps=0x407f020f, sd3_bus_mode=0x3, v18_fixup_failed false, signal_voltage
> =0x1.
> [  115.167366] [5:    kworker/5:2:  207] [TEST] mmc_sd_init_card: 1149: rocr
> 0xc1ff8000, S18A, uhs.
> [  115.168041] [5:    kworker/5:2:  207] [TEST] mmc_sd_init_uhs_card: before
> update: caps 0x407f020f, sd3_bus_mode = 3, sd_bus_speed = 3, card->ocr =
> 0x40000.
> [  115.168051] [5:    kworker/5:2:  207] [TEST] sd_update_bus_speed_mode:
> caps 0x407f020f, sd3_bus_mode = 3, sd_bus_speed = 1, card->ocr = 0x40000.
> [  115.169176] [5:    kworker/5:2:  207] [TEST] sd_set_bus_speed_mode:
> sd_bus_speed=1, timing=4, uhs_max_dtr=50000000, card->ocr=0x40000.
> 
> TO-BE : TEST log with this commit
> // resume : issue occurs : SDcard doesn't release busy for checking 10
> times
> [ 1843.594805] [4:    kworker/4:5:21512] [TEST] mmc_sd_get_cid: ocr
> 0x41040000(pocr 0x40000), retries 0.
> [ 1843.594812] [4:    kworker/4:5:21512] mmc0: Skipping voltage switch
> [ 1843.772555] [4:    kworker/4:5:21512] [TEST] mmc_sd_init_card: 1122:
> caps=0x407f020f, sd3_bus_mode=0x1f, v18_fixup_failed false, signal_voltage
> =0x0.
> // no update sd3_bus_mode value
> [ 1843.772563] [4:    kworker/4:5:21512] [TEST] mmc_sd_init_card: 1164:
> switch hs.
> // next resume : the SDcard initializes to SDR104
> [ 1844.191295] [5:   kworker/5:93: 2282] [TEST] mmc_sd_init_card: 1122:
> caps=0x407f020f, sd3_bus_mode=0x1f, v18_fixup_failed false, signal_voltage
> =0x1.
> [ 1844.191315] [5:   kworker/5:93: 2282] [TEST] mmc_sd_init_card: 1154:
> rocr 0xc1ff8000, S18A, uhs.
> [ 1844.192175] [5:   kworker/5:93: 2282] [TEST] mmc_sd_init_uhs_card:
> before update: caps 0x407f020f, sd3_bus_mode = 0x1f, sd_bus_speed = 3,
> card->ocr = 0x40000.
> [ 1844.192187] [5:   kworker/5:93: 2282] [TEST] sd_update_bus_speed_mode:
> caps 0x407f020f, sd3_bus_mode = 0x1f, sd_bus_speed = 3, card->ocr =
> 0x40000.
> [ 1844.198697] [5:   kworker/5:93: 2282] [TEST] sd_set_bus_speed_mode:
> sd_bus_speed=3, timing=6, uhs_max_dtr=208000000, card->ocr=0x40000.
> 
> Signed-off-by: Seunghui Lee <sh043.lee@samsung.com>
> Tested-by: DooHyun Hwang <dh0421.hwang@samsung.com>
> ---
>  drivers/mmc/core/sd.c | 47 ++-----------------------------------------
>  1 file changed, 2 insertions(+), 45 deletions(-)
> 
> diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c index
> cee4c0b59f43..4e3d39956185 100644
> --- a/drivers/mmc/core/sd.c
> +++ b/drivers/mmc/core/sd.c
> @@ -1001,18 +1001,6 @@ unsigned mmc_sd_get_max_clock(struct mmc_card *card)
>  	return max_dtr;
>  }
> 
> -static bool mmc_sd_card_using_v18(struct mmc_card *card) -{
> -	/*
> -	 * According to the SD spec., the Bus Speed Mode (function group 1)
> bits
> -	 * 2 to 4 are zero if the card is initialized at 3.3V signal level.
> Thus
> -	 * they can be used to determine if the card has already switched
> to
> -	 * 1.8V signaling.
> -	 */
> -	return card->sw_caps.sd3_bus_mode &
> -	       (SD_MODE_UHS_SDR50 | SD_MODE_UHS_SDR104 | SD_MODE_UHS_DDR50);
> -}
> -
>  static int sd_write_ext_reg(struct mmc_card *card, u8 fno, u8 page, u16
> offset,
>  			    u8 reg_data)
>  {
> @@ -1400,10 +1388,9 @@ static int mmc_sd_init_card(struct mmc_host *host,
> u32 ocr,
>  	int err;
>  	u32 cid[4];
>  	u32 rocr = 0;
> -	bool v18_fixup_failed = false;
> 
>  	WARN_ON(!host->claimed);
> -retry:
> +
>  	err = mmc_sd_get_cid(host, ocr, cid, &rocr);
>  	if (err)
>  		return err;
> @@ -1472,36 +1459,6 @@ static int mmc_sd_init_card(struct mmc_host *host,
> u32 ocr,
>  	if (err)
>  		goto free_card;
> 
> -	/*
> -	 * If the card has not been power cycled, it may still be using
> 1.8V
> -	 * signaling. Detect that situation and try to initialize a UHS-I
> (1.8V)
> -	 * transfer mode.
> -	 */
> -	if (!v18_fixup_failed && !mmc_host_is_spi(host) &&
> mmc_host_uhs(host) &&
> -	    mmc_sd_card_using_v18(card) &&
> -	    host->ios.signal_voltage != MMC_SIGNAL_VOLTAGE_180) {
> -		/*
> -		 * Re-read switch information in case it has changed since
> -		 * oldcard was initialized.
> -		 */
> -		if (oldcard) {
> -			err = mmc_read_switch(card);
> -			if (err)
> -				goto free_card;
> -		}
> -		if (mmc_sd_card_using_v18(card)) {
> -			if (mmc_host_set_uhs_voltage(host) ||
> -			    mmc_sd_init_uhs_card(card)) {
> -				v18_fixup_failed = true;
> -				mmc_power_cycle(host, ocr);
> -				if (!oldcard)
> -					mmc_remove_card(card);
> -				goto retry;
> -			}
> -			goto done;
> -		}
> -	}
> -
>  	/* Initialization sequence for UHS-I cards */
>  	if (rocr & SD_ROCR_S18A && mmc_host_uhs(host)) {
>  		err = mmc_sd_init_uhs_card(card);
> @@ -1566,7 +1523,7 @@ static int mmc_sd_init_card(struct mmc_host *host,
> u32 ocr,
>  		err = -EINVAL;
>  		goto free_card;
>  	}
> -done:
> +
>  	host->card = card;
>  	return 0;
> 
> --
> 2.29.0

Dear All,

Please review this commit.

Once the SDR104 SD card fails to switch voltage,
there is no chance to work SDR104 bus speed again
due to update sd3_bus_mode.

To fix this regression issue, do not update sd3_bus_mode.
And then it has the chance to work SDR104 again.

AS-IS:
voltage_switch fail -> mmc_read_switch() -> HS mode
next system resume
voltage switch success -> SDR25 mode

TO-BE:
Voltage switch fail -> HS mode
Next system resume
Voltage switch success -> SDR104 mode

And plus, mmc_set_uhs_voltage() has power_cycle now.
It means that if voltage switch fails,
the card initializes 3.3V signal level.

Regards,
Seunghui Lee.
Adrian Hunter July 26, 2022, 10:56 a.m. UTC | #2
On 26/07/22 05:56, Seunghui Lee wrote:
>> -----Original Message-----
>> From: Seunghui Lee <sh043.lee@samsung.com>
>> Sent: Thursday, July 21, 2022 2:59 PM
>> To: ulf.hansson@linaro.org; linux-mmc@vger.kernel.org;
>> adrian.hunter@intel.com
>> Cc: Seunghui Lee <sh043.lee@samsung.com>; DooHyun Hwang
>> <dh0421.hwang@samsung.com>
>> Subject: [PATCH] mmc: sd: Remove the patch that fix signal voltage when
>> there is no power cycle
>>
>> At first, all error flow of mmc_set_uhs_voltage() has power cycle except
>> R1_ERROR and no start_signal_voltage_switch() func pointer.
>>
>> There is the performance regression issue of SDR104 SD card from the
>> market VOC. Normally, once a SDR104 SD card fails to switch voltage, it
>> works HS mode.
>> And then it initializes SDR104 mode after system resume or error handling.
>>
>> However, with below patch,
>> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/
>> drivers/mmc/core/sd.c?id=6a11fc47f175c8d87018e89cb58e2d36c66534cb
>> Once a SD card does, it initializes SDR25 mode forever after system resume
>> or error handling(re-initialized).
>> Host updates sd3_bus_mode by calling mmc_read_switch(), the value of
>> sd3_bus_mode doesn't set for SDR104, SDR50 and DDR50 mode.
>>
>> So, if host doesn't update sd3_bus_mode, the SD card works SDR104 mode
>> after system resume or error-handling.
>>
>> Here is an example.
>>
>> AS-IS : test log
>> // normal case : sd3_bus_mode = 0x1F, sd_bus_speed = SDR104, clock 208MHz
>> [  111.907789] [1:    kworker/1:3:  772] [TEST] mmc_sd_init_card: 1119:
>> caps=0x407f020f, sd3_bus_mode=0x1f, v18_fixup_failed false, signal_voltage
>> =0x1.
>> [  111.907824] [1:    kworker/1:3:  772] [TEST] mmc_sd_init_card: 1149: rocr
>> 0xc1ff8000, S18A, uhs.
>> [  111.908707] [1:    kworker/1:3:  772] [TEST] sd_update_bus_speed_mode:
>> caps 0x407f020f, sd3_bus_mode = 0x1f, sd_bus_speed = 3, card->ocr =
>> 0x40000.
>> [  111.912484] [1:    kworker/1:3:  772] [TEST] sd_set_bus_speed_mode:
>> sd_bus_speed=3, timing=6, uhs_max_dtr=208000000, card->ocr=0x40000.
>> // resume : issue occurs : SDcard doesn't release busy for checking 10
>> times
>> [  112.096550] [5:    kworker/5:2:  207] [TEST] mmc_sd_init_card: 1040:
>> card->ocr 0x40000.
>> [  112.096560] [5:    kworker/5:2:  207] [TEST] mmc_sd_get_cid: ocr
>> 0x40000(pocr 0x40000), retries 10.
>> ...
>> [  114.531129] [5:    kworker/5:2:  207] [TEST] mmc_power_cycle.
>> [  114.579500] [5:    kworker/5:2:  207] [TEST] mmc_sd_get_cid: ocr
>> 0x41040000(pocr 0x40000), retries 0.
>> [  114.579506] [5:    kworker/5:2:  207] mmc0: Skipping voltage switch
>> [  114.757575] [5:    kworker/5:2:  207] [TEST] mmc_sd_init_card: 1119:
>> caps=0x407f020f, sd3_bus_mode=0x1f, v18_fixup_failed false, signal_voltage
>> =0x0.
>> [  114.757583] [5:    kworker/5:2:  207] [TEST] mmc_sd_init_card: 1128:
>> switch with oldcard.
>> [  114.759742] [5:    kworker/5:2:  207] [TEST] mmc_read_switch: sd_switch
>> ret 0, sd3_bus_mode=3.
>> // sd3_bus_mode = 0x3 supports HS, SDR25 and SDR12
>> [  114.759750] [5:    kworker/5:2:  207] [TEST] mmc_sd_init_card: 1157:
>> switch hs.
>> // next resume : the SDcard initializes to SDR25(HS) mode(sd_bus_speed = 1)
>> by sd3_bus_mode setting with clk 50MHz
>> [  114.968346] [5:    kworker/5:2:  207] [TEST] mmc_sd_init_card: 1040:
>> card->ocr 0x40000.
>> [  114.968359] [5:    kworker/5:2:  207] [TEST] mmc_sd_get_cid: ocr
>> 0x40000(pocr 0x40000), retries 10.
>> [  115.167346] [5:    kworker/5:2:  207] [TEST] mmc_sd_init_card: 1119:
>> caps=0x407f020f, sd3_bus_mode=0x3, v18_fixup_failed false, signal_voltage
>> =0x1.
>> [  115.167366] [5:    kworker/5:2:  207] [TEST] mmc_sd_init_card: 1149: rocr
>> 0xc1ff8000, S18A, uhs.
>> [  115.168041] [5:    kworker/5:2:  207] [TEST] mmc_sd_init_uhs_card: before
>> update: caps 0x407f020f, sd3_bus_mode = 3, sd_bus_speed = 3, card->ocr =
>> 0x40000.
>> [  115.168051] [5:    kworker/5:2:  207] [TEST] sd_update_bus_speed_mode:
>> caps 0x407f020f, sd3_bus_mode = 3, sd_bus_speed = 1, card->ocr = 0x40000.
>> [  115.169176] [5:    kworker/5:2:  207] [TEST] sd_set_bus_speed_mode:
>> sd_bus_speed=1, timing=4, uhs_max_dtr=50000000, card->ocr=0x40000.
>>
>> TO-BE : TEST log with this commit
>> // resume : issue occurs : SDcard doesn't release busy for checking 10
>> times
>> [ 1843.594805] [4:    kworker/4:5:21512] [TEST] mmc_sd_get_cid: ocr
>> 0x41040000(pocr 0x40000), retries 0.
>> [ 1843.594812] [4:    kworker/4:5:21512] mmc0: Skipping voltage switch
>> [ 1843.772555] [4:    kworker/4:5:21512] [TEST] mmc_sd_init_card: 1122:
>> caps=0x407f020f, sd3_bus_mode=0x1f, v18_fixup_failed false, signal_voltage
>> =0x0.
>> // no update sd3_bus_mode value
>> [ 1843.772563] [4:    kworker/4:5:21512] [TEST] mmc_sd_init_card: 1164:
>> switch hs.
>> // next resume : the SDcard initializes to SDR104
>> [ 1844.191295] [5:   kworker/5:93: 2282] [TEST] mmc_sd_init_card: 1122:
>> caps=0x407f020f, sd3_bus_mode=0x1f, v18_fixup_failed false, signal_voltage
>> =0x1.
>> [ 1844.191315] [5:   kworker/5:93: 2282] [TEST] mmc_sd_init_card: 1154:
>> rocr 0xc1ff8000, S18A, uhs.
>> [ 1844.192175] [5:   kworker/5:93: 2282] [TEST] mmc_sd_init_uhs_card:
>> before update: caps 0x407f020f, sd3_bus_mode = 0x1f, sd_bus_speed = 3,
>> card->ocr = 0x40000.
>> [ 1844.192187] [5:   kworker/5:93: 2282] [TEST] sd_update_bus_speed_mode:
>> caps 0x407f020f, sd3_bus_mode = 0x1f, sd_bus_speed = 3, card->ocr =
>> 0x40000.
>> [ 1844.198697] [5:   kworker/5:93: 2282] [TEST] sd_set_bus_speed_mode:
>> sd_bus_speed=3, timing=6, uhs_max_dtr=208000000, card->ocr=0x40000.
>>
>> Signed-off-by: Seunghui Lee <sh043.lee@samsung.com>
>> Tested-by: DooHyun Hwang <dh0421.hwang@samsung.com>
>> ---
>>  drivers/mmc/core/sd.c | 47 ++-----------------------------------------
>>  1 file changed, 2 insertions(+), 45 deletions(-)
>>
>> diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c index
>> cee4c0b59f43..4e3d39956185 100644
>> --- a/drivers/mmc/core/sd.c
>> +++ b/drivers/mmc/core/sd.c
>> @@ -1001,18 +1001,6 @@ unsigned mmc_sd_get_max_clock(struct mmc_card *card)
>>  	return max_dtr;
>>  }
>>
>> -static bool mmc_sd_card_using_v18(struct mmc_card *card) -{
>> -	/*
>> -	 * According to the SD spec., the Bus Speed Mode (function group 1)
>> bits
>> -	 * 2 to 4 are zero if the card is initialized at 3.3V signal level.
>> Thus
>> -	 * they can be used to determine if the card has already switched
>> to
>> -	 * 1.8V signaling.
>> -	 */
>> -	return card->sw_caps.sd3_bus_mode &
>> -	       (SD_MODE_UHS_SDR50 | SD_MODE_UHS_SDR104 | SD_MODE_UHS_DDR50);
>> -}
>> -
>>  static int sd_write_ext_reg(struct mmc_card *card, u8 fno, u8 page, u16
>> offset,
>>  			    u8 reg_data)
>>  {
>> @@ -1400,10 +1388,9 @@ static int mmc_sd_init_card(struct mmc_host *host,
>> u32 ocr,
>>  	int err;
>>  	u32 cid[4];
>>  	u32 rocr = 0;
>> -	bool v18_fixup_failed = false;
>>
>>  	WARN_ON(!host->claimed);
>> -retry:
>> +
>>  	err = mmc_sd_get_cid(host, ocr, cid, &rocr);
>>  	if (err)
>>  		return err;
>> @@ -1472,36 +1459,6 @@ static int mmc_sd_init_card(struct mmc_host *host,
>> u32 ocr,
>>  	if (err)
>>  		goto free_card;
>>
>> -	/*
>> -	 * If the card has not been power cycled, it may still be using
>> 1.8V
>> -	 * signaling. Detect that situation and try to initialize a UHS-I
>> (1.8V)
>> -	 * transfer mode.
>> -	 */
>> -	if (!v18_fixup_failed && !mmc_host_is_spi(host) &&
>> mmc_host_uhs(host) &&
>> -	    mmc_sd_card_using_v18(card) &&
>> -	    host->ios.signal_voltage != MMC_SIGNAL_VOLTAGE_180) {
>> -		/*
>> -		 * Re-read switch information in case it has changed since
>> -		 * oldcard was initialized.
>> -		 */
>> -		if (oldcard) {
>> -			err = mmc_read_switch(card);
>> -			if (err)
>> -				goto free_card;
>> -		}
>> -		if (mmc_sd_card_using_v18(card)) {
>> -			if (mmc_host_set_uhs_voltage(host) ||
>> -			    mmc_sd_init_uhs_card(card)) {
>> -				v18_fixup_failed = true;
>> -				mmc_power_cycle(host, ocr);
>> -				if (!oldcard)
>> -					mmc_remove_card(card);
>> -				goto retry;
>> -			}
>> -			goto done;
>> -		}
>> -	}
>> -
>>  	/* Initialization sequence for UHS-I cards */
>>  	if (rocr & SD_ROCR_S18A && mmc_host_uhs(host)) {
>>  		err = mmc_sd_init_uhs_card(card);
>> @@ -1566,7 +1523,7 @@ static int mmc_sd_init_card(struct mmc_host *host,
>> u32 ocr,
>>  		err = -EINVAL;
>>  		goto free_card;
>>  	}
>> -done:
>> +
>>  	host->card = card;
>>  	return 0;
>>
>> --
>> 2.29.0
> 
> Dear All,
> 
> Please review this commit.

I have started to look at it, but my time is limited at the
moment.

Note the original patch is 5 years old and fixes a real
problem, so we don't want to just throw it away.

> 
> Once the SDR104 SD card fails to switch voltage,
> there is no chance to work SDR104 bus speed again
> due to update sd3_bus_mode.
> 
> To fix this regression issue, do not update sd3_bus_mode.
> And then it has the chance to work SDR104 again.
> 
> AS-IS:
> voltage_switch fail -> mmc_read_switch() -> HS mode
> next system resume
> voltage switch success -> SDR25 mode
> 
> TO-BE:
> Voltage switch fail -> HS mode
> Next system resume
> Voltage switch success -> SDR104 mode
> 
> And plus, mmc_set_uhs_voltage() has power_cycle now.
> It means that if voltage switch fails,
> the card initializes 3.3V signal level.
> 
> Regards,
> Seunghui Lee.
>
이승희 Aug. 8, 2022, 8:24 a.m. UTC | #3
> -----Original Message-----
> From: Adrian Hunter <adrian.hunter@intel.com>
> Sent: Tuesday, July 26, 2022 7:57 PM
> To: Seunghui Lee <sh043.lee@samsung.com>; linux-mmc@vger.kernel.org;
> adrian.hunter@intel.com
> Cc: 'DooHyun Hwang' <dh0421.hwang@samsung.com>
> Subject: Re: [PATCH] mmc: sd: Remove the patch that fix signal voltage
> when there is no power cycle
> 
> On 26/07/22 05:56, Seunghui Lee wrote:
> >> -----Original Message-----
> >> From: Seunghui Lee <sh043.lee@samsung.com>
> >> Sent: Thursday, July 21, 2022 2:59 PM
> >> To: ulf.hansson@linaro.org; linux-mmc@vger.kernel.org;
> >> adrian.hunter@intel.com
> >> Cc: Seunghui Lee <sh043.lee@samsung.com>; DooHyun Hwang
> >> <dh0421.hwang@samsung.com>
> >> Subject: [PATCH] mmc: sd: Remove the patch that fix signal voltage
> >> when there is no power cycle
> >>
> >> At first, all error flow of mmc_set_uhs_voltage() has power cycle
> >> except R1_ERROR and no start_signal_voltage_switch() func pointer.
> >>
> >> There is the performance regression issue of SDR104 SD card from the
> >> market VOC. Normally, once a SDR104 SD card fails to switch voltage,
> >> it works HS mode.
> >> And then it initializes SDR104 mode after system resume or error
> handling.
> >>
> >> However, with below patch,
> >> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/co
> >> mmit/
> >> drivers/mmc/core/sd.c?id=6a11fc47f175c8d87018e89cb58e2d36c66534cb
> >> Once a SD card does, it initializes SDR25 mode forever after system
> >> resume or error handling(re-initialized).
> >> Host updates sd3_bus_mode by calling mmc_read_switch(), the value of
> >> sd3_bus_mode doesn't set for SDR104, SDR50 and DDR50 mode.
> >>
> >> So, if host doesn't update sd3_bus_mode, the SD card works SDR104
> >> mode after system resume or error-handling.
> >>
> >> Here is an example.
> >>
> >> AS-IS : test log
> >> // normal case : sd3_bus_mode = 0x1F, sd_bus_speed = SDR104, clock
> 208MHz
> >> [  111.907789] [1:    kworker/1:3:  772] [TEST] mmc_sd_init_card: 1119:
> >> caps=0x407f020f, sd3_bus_mode=0x1f, v18_fixup_failed false,
> >> signal_voltage =0x1.
> >> [  111.907824] [1:    kworker/1:3:  772] [TEST] mmc_sd_init_card: 1149:
> rocr
> >> 0xc1ff8000, S18A, uhs.
> >> [  111.908707] [1:    kworker/1:3:  772] [TEST] sd_update_bus_speed_mode:
> >> caps 0x407f020f, sd3_bus_mode = 0x1f, sd_bus_speed = 3, card->ocr =
> >> 0x40000.
> >> [  111.912484] [1:    kworker/1:3:  772] [TEST] sd_set_bus_speed_mode:
> >> sd_bus_speed=3, timing=6, uhs_max_dtr=208000000, card->ocr=0x40000.
> >> // resume : issue occurs : SDcard doesn't release busy for checking
> >> 10 times
> >> [  112.096550] [5:    kworker/5:2:  207] [TEST] mmc_sd_init_card: 1040:
> >> card->ocr 0x40000.
> >> [  112.096560] [5:    kworker/5:2:  207] [TEST] mmc_sd_get_cid: ocr
> >> 0x40000(pocr 0x40000), retries 10.
> >> ...
> >> [  114.531129] [5:    kworker/5:2:  207] [TEST] mmc_power_cycle.
> >> [  114.579500] [5:    kworker/5:2:  207] [TEST] mmc_sd_get_cid: ocr
> >> 0x41040000(pocr 0x40000), retries 0.
> >> [  114.579506] [5:    kworker/5:2:  207] mmc0: Skipping voltage switch
> >> [  114.757575] [5:    kworker/5:2:  207] [TEST] mmc_sd_init_card: 1119:
> >> caps=0x407f020f, sd3_bus_mode=0x1f, v18_fixup_failed false,
> >> signal_voltage =0x0.
> >> [  114.757583] [5:    kworker/5:2:  207] [TEST] mmc_sd_init_card: 1128:
> >> switch with oldcard.
> >> [  114.759742] [5:    kworker/5:2:  207] [TEST] mmc_read_switch:
> sd_switch
> >> ret 0, sd3_bus_mode=3.
> >> // sd3_bus_mode = 0x3 supports HS, SDR25 and SDR12
> >> [  114.759750] [5:    kworker/5:2:  207] [TEST] mmc_sd_init_card: 1157:
> >> switch hs.
> >> // next resume : the SDcard initializes to SDR25(HS)
> >> mode(sd_bus_speed = 1) by sd3_bus_mode setting with clk 50MHz
> >> [  114.968346] [5:    kworker/5:2:  207] [TEST] mmc_sd_init_card: 1040:
> >> card->ocr 0x40000.
> >> [  114.968359] [5:    kworker/5:2:  207] [TEST] mmc_sd_get_cid: ocr
> >> 0x40000(pocr 0x40000), retries 10.
> >> [  115.167346] [5:    kworker/5:2:  207] [TEST] mmc_sd_init_card: 1119:
> >> caps=0x407f020f, sd3_bus_mode=0x3, v18_fixup_failed false,
> >> signal_voltage =0x1.
> >> [  115.167366] [5:    kworker/5:2:  207] [TEST] mmc_sd_init_card: 1149:
> rocr
> >> 0xc1ff8000, S18A, uhs.
> >> [  115.168041] [5:    kworker/5:2:  207] [TEST] mmc_sd_init_uhs_card:
> before
> >> update: caps 0x407f020f, sd3_bus_mode = 3, sd_bus_speed = 3,
> >> card->ocr = 0x40000.
> >> [  115.168051] [5:    kworker/5:2:  207] [TEST] sd_update_bus_speed_mode:
> >> caps 0x407f020f, sd3_bus_mode = 3, sd_bus_speed = 1, card->ocr =
> 0x40000.
> >> [  115.169176] [5:    kworker/5:2:  207] [TEST] sd_set_bus_speed_mode:
> >> sd_bus_speed=1, timing=4, uhs_max_dtr=50000000, card->ocr=0x40000.
> >>
> >> TO-BE : TEST log with this commit
> >> // resume : issue occurs : SDcard doesn't release busy for checking
> >> 10 times
> >> [ 1843.594805] [4:    kworker/4:5:21512] [TEST] mmc_sd_get_cid: ocr
> >> 0x41040000(pocr 0x40000), retries 0.
> >> [ 1843.594812] [4:    kworker/4:5:21512] mmc0: Skipping voltage switch
> >> [ 1843.772555] [4:    kworker/4:5:21512] [TEST] mmc_sd_init_card: 1122:
> >> caps=0x407f020f, sd3_bus_mode=0x1f, v18_fixup_failed false,
> >> signal_voltage =0x0.
> >> // no update sd3_bus_mode value
> >> [ 1843.772563] [4:    kworker/4:5:21512] [TEST] mmc_sd_init_card: 1164:
> >> switch hs.
> >> // next resume : the SDcard initializes to SDR104
> >> [ 1844.191295] [5:   kworker/5:93: 2282] [TEST] mmc_sd_init_card: 1122:
> >> caps=0x407f020f, sd3_bus_mode=0x1f, v18_fixup_failed false,
> >> signal_voltage =0x1.
> >> [ 1844.191315] [5:   kworker/5:93: 2282] [TEST] mmc_sd_init_card: 1154:
> >> rocr 0xc1ff8000, S18A, uhs.
> >> [ 1844.192175] [5:   kworker/5:93: 2282] [TEST] mmc_sd_init_uhs_card:
> >> before update: caps 0x407f020f, sd3_bus_mode = 0x1f, sd_bus_speed =
> >> 3,
> >> card->ocr = 0x40000.
> >> [ 1844.192187] [5:   kworker/5:93: 2282] [TEST]
> sd_update_bus_speed_mode:
> >> caps 0x407f020f, sd3_bus_mode = 0x1f, sd_bus_speed = 3, card->ocr =
> >> 0x40000.
> >> [ 1844.198697] [5:   kworker/5:93: 2282] [TEST] sd_set_bus_speed_mode:
> >> sd_bus_speed=3, timing=6, uhs_max_dtr=208000000, card->ocr=0x40000.
> >>
> >> Signed-off-by: Seunghui Lee <sh043.lee@samsung.com>
> >> Tested-by: DooHyun Hwang <dh0421.hwang@samsung.com>
> >> ---
> >>  drivers/mmc/core/sd.c | 47
> >> ++-----------------------------------------
> >>  1 file changed, 2 insertions(+), 45 deletions(-)
> >>
> >> diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c index
> >> cee4c0b59f43..4e3d39956185 100644
> >> --- a/drivers/mmc/core/sd.c
> >> +++ b/drivers/mmc/core/sd.c
> >> @@ -1001,18 +1001,6 @@ unsigned mmc_sd_get_max_clock(struct mmc_card
> *card)
> >>  	return max_dtr;
> >>  }
> >>
> >> -static bool mmc_sd_card_using_v18(struct mmc_card *card) -{
> >> -	/*
> >> -	 * According to the SD spec., the Bus Speed Mode (function group 1)
> >> bits
> >> -	 * 2 to 4 are zero if the card is initialized at 3.3V signal level.
> >> Thus
> >> -	 * they can be used to determine if the card has already switched
> >> to
> >> -	 * 1.8V signaling.
> >> -	 */
> >> -	return card->sw_caps.sd3_bus_mode &
> >> -	       (SD_MODE_UHS_SDR50 | SD_MODE_UHS_SDR104 | SD_MODE_UHS_DDR50);
> >> -}
> >> -
> >>  static int sd_write_ext_reg(struct mmc_card *card, u8 fno, u8 page,
> >> u16 offset,
> >>  			    u8 reg_data)
> >>  {
> >> @@ -1400,10 +1388,9 @@ static int mmc_sd_init_card(struct mmc_host
> >> *host,
> >> u32 ocr,
> >>  	int err;
> >>  	u32 cid[4];
> >>  	u32 rocr = 0;
> >> -	bool v18_fixup_failed = false;
> >>
> >>  	WARN_ON(!host->claimed);
> >> -retry:
> >> +
> >>  	err = mmc_sd_get_cid(host, ocr, cid, &rocr);
> >>  	if (err)
> >>  		return err;
> >> @@ -1472,36 +1459,6 @@ static int mmc_sd_init_card(struct mmc_host
> >> *host,
> >> u32 ocr,
> >>  	if (err)
> >>  		goto free_card;
> >>
> >> -	/*
> >> -	 * If the card has not been power cycled, it may still be using
> >> 1.8V
> >> -	 * signaling. Detect that situation and try to initialize a UHS-I
> >> (1.8V)
> >> -	 * transfer mode.
> >> -	 */
> >> -	if (!v18_fixup_failed && !mmc_host_is_spi(host) &&
> >> mmc_host_uhs(host) &&
> >> -	    mmc_sd_card_using_v18(card) &&
> >> -	    host->ios.signal_voltage != MMC_SIGNAL_VOLTAGE_180) {
> >> -		/*
> >> -		 * Re-read switch information in case it has changed since
> >> -		 * oldcard was initialized.
> >> -		 */
> >> -		if (oldcard) {
> >> -			err = mmc_read_switch(card);
> >> -			if (err)
> >> -				goto free_card;
> >> -		}
> >> -		if (mmc_sd_card_using_v18(card)) {
> >> -			if (mmc_host_set_uhs_voltage(host) ||
> >> -			    mmc_sd_init_uhs_card(card)) {
> >> -				v18_fixup_failed = true;
> >> -				mmc_power_cycle(host, ocr);
> >> -				if (!oldcard)
> >> -					mmc_remove_card(card);
> >> -				goto retry;
> >> -			}
> >> -			goto done;
> >> -		}
> >> -	}
> >> -
> >>  	/* Initialization sequence for UHS-I cards */
> >>  	if (rocr & SD_ROCR_S18A && mmc_host_uhs(host)) {
> >>  		err = mmc_sd_init_uhs_card(card);
> >> @@ -1566,7 +1523,7 @@ static int mmc_sd_init_card(struct mmc_host
> >> *host,
> >> u32 ocr,
> >>  		err = -EINVAL;
> >>  		goto free_card;
> >>  	}
> >> -done:
> >> +
> >>  	host->card = card;
> >>  	return 0;
> >>
> >> --
> >> 2.29.0
> >
> > Dear All,
> >
> > Please review this commit.
> 
> I have started to look at it, but my time is limited at the moment.
> 
> Note the original patch is 5 years old and fixes a real problem, so we
> don't want to just throw it away.
> 

Dear Mr. hunter,

Could you check this with below patch?

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/drivers/mmc/core/core.c?id=147186f531ae49c18b7a9091a2c40e83b3d95649

In the mmc_set_uhs_voltaga func(),
once it occurs error, it has power_cycle except R1_ERROR with CMD11.
So, When mmc_set_uhs_voltage() return error,
host and card can't leave 1.8V voltage.

Regards,

> >
> > Once the SDR104 SD card fails to switch voltage, there is no chance to
> > work SDR104 bus speed again due to update sd3_bus_mode.
> >
> > To fix this regression issue, do not update sd3_bus_mode.
> > And then it has the chance to work SDR104 again.
> >
> > AS-IS:
> > voltage_switch fail -> mmc_read_switch() -> HS mode next system resume
> > voltage switch success -> SDR25 mode
> >
> > TO-BE:
> > Voltage switch fail -> HS mode
> > Next system resume
> > Voltage switch success -> SDR104 mode
> >
> > And plus, mmc_set_uhs_voltage() has power_cycle now.
> > It means that if voltage switch fails, the card initializes 3.3V
> > signal level.
> >
> > Regards,
> > Seunghui Lee.
> >
Adrian Hunter Aug. 9, 2022, 5:36 a.m. UTC | #4
On 8/08/22 11:24, Seunghui Lee wrote:
>> -----Original Message-----
>> From: Adrian Hunter <adrian.hunter@intel.com>
>> Sent: Tuesday, July 26, 2022 7:57 PM
>> To: Seunghui Lee <sh043.lee@samsung.com>; linux-mmc@vger.kernel.org;
>> adrian.hunter@intel.com
>> Cc: 'DooHyun Hwang' <dh0421.hwang@samsung.com>
>> Subject: Re: [PATCH] mmc: sd: Remove the patch that fix signal voltage
>> when there is no power cycle
>>
>> On 26/07/22 05:56, Seunghui Lee wrote:
>>>> -----Original Message-----
>>>> From: Seunghui Lee <sh043.lee@samsung.com>
>>>> Sent: Thursday, July 21, 2022 2:59 PM
>>>> To: ulf.hansson@linaro.org; linux-mmc@vger.kernel.org;
>>>> adrian.hunter@intel.com
>>>> Cc: Seunghui Lee <sh043.lee@samsung.com>; DooHyun Hwang
>>>> <dh0421.hwang@samsung.com>
>>>> Subject: [PATCH] mmc: sd: Remove the patch that fix signal voltage
>>>> when there is no power cycle
>>>>
>>>> At first, all error flow of mmc_set_uhs_voltage() has power cycle
>>>> except R1_ERROR and no start_signal_voltage_switch() func pointer.
>>>>
>>>> There is the performance regression issue of SDR104 SD card from the
>>>> market VOC. Normally, once a SDR104 SD card fails to switch voltage,
>>>> it works HS mode.
>>>> And then it initializes SDR104 mode after system resume or error
>> handling.
>>>>
>>>> However, with below patch,
>>>> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/co
>>>> mmit/
>>>> drivers/mmc/core/sd.c?id=6a11fc47f175c8d87018e89cb58e2d36c66534cb
>>>> Once a SD card does, it initializes SDR25 mode forever after system
>>>> resume or error handling(re-initialized).
>>>> Host updates sd3_bus_mode by calling mmc_read_switch(), the value of
>>>> sd3_bus_mode doesn't set for SDR104, SDR50 and DDR50 mode.
>>>>
>>>> So, if host doesn't update sd3_bus_mode, the SD card works SDR104
>>>> mode after system resume or error-handling.
>>>>
>>>> Here is an example.
>>>>
>>>> AS-IS : test log
>>>> // normal case : sd3_bus_mode = 0x1F, sd_bus_speed = SDR104, clock
>> 208MHz
>>>> [  111.907789] [1:    kworker/1:3:  772] [TEST] mmc_sd_init_card: 1119:
>>>> caps=0x407f020f, sd3_bus_mode=0x1f, v18_fixup_failed false,
>>>> signal_voltage =0x1.
>>>> [  111.907824] [1:    kworker/1:3:  772] [TEST] mmc_sd_init_card: 1149:
>> rocr
>>>> 0xc1ff8000, S18A, uhs.
>>>> [  111.908707] [1:    kworker/1:3:  772] [TEST] sd_update_bus_speed_mode:
>>>> caps 0x407f020f, sd3_bus_mode = 0x1f, sd_bus_speed = 3, card->ocr =
>>>> 0x40000.
>>>> [  111.912484] [1:    kworker/1:3:  772] [TEST] sd_set_bus_speed_mode:
>>>> sd_bus_speed=3, timing=6, uhs_max_dtr=208000000, card->ocr=0x40000.
>>>> // resume : issue occurs : SDcard doesn't release busy for checking
>>>> 10 times
>>>> [  112.096550] [5:    kworker/5:2:  207] [TEST] mmc_sd_init_card: 1040:
>>>> card->ocr 0x40000.
>>>> [  112.096560] [5:    kworker/5:2:  207] [TEST] mmc_sd_get_cid: ocr
>>>> 0x40000(pocr 0x40000), retries 10.
>>>> ...
>>>> [  114.531129] [5:    kworker/5:2:  207] [TEST] mmc_power_cycle.
>>>> [  114.579500] [5:    kworker/5:2:  207] [TEST] mmc_sd_get_cid: ocr
>>>> 0x41040000(pocr 0x40000), retries 0.
>>>> [  114.579506] [5:    kworker/5:2:  207] mmc0: Skipping voltage switch
>>>> [  114.757575] [5:    kworker/5:2:  207] [TEST] mmc_sd_init_card: 1119:
>>>> caps=0x407f020f, sd3_bus_mode=0x1f, v18_fixup_failed false,
>>>> signal_voltage =0x0.
>>>> [  114.757583] [5:    kworker/5:2:  207] [TEST] mmc_sd_init_card: 1128:
>>>> switch with oldcard.
>>>> [  114.759742] [5:    kworker/5:2:  207] [TEST] mmc_read_switch:
>> sd_switch
>>>> ret 0, sd3_bus_mode=3.
>>>> // sd3_bus_mode = 0x3 supports HS, SDR25 and SDR12
>>>> [  114.759750] [5:    kworker/5:2:  207] [TEST] mmc_sd_init_card: 1157:
>>>> switch hs.
>>>> // next resume : the SDcard initializes to SDR25(HS)
>>>> mode(sd_bus_speed = 1) by sd3_bus_mode setting with clk 50MHz
>>>> [  114.968346] [5:    kworker/5:2:  207] [TEST] mmc_sd_init_card: 1040:
>>>> card->ocr 0x40000.
>>>> [  114.968359] [5:    kworker/5:2:  207] [TEST] mmc_sd_get_cid: ocr
>>>> 0x40000(pocr 0x40000), retries 10.
>>>> [  115.167346] [5:    kworker/5:2:  207] [TEST] mmc_sd_init_card: 1119:
>>>> caps=0x407f020f, sd3_bus_mode=0x3, v18_fixup_failed false,
>>>> signal_voltage =0x1.
>>>> [  115.167366] [5:    kworker/5:2:  207] [TEST] mmc_sd_init_card: 1149:
>> rocr
>>>> 0xc1ff8000, S18A, uhs.
>>>> [  115.168041] [5:    kworker/5:2:  207] [TEST] mmc_sd_init_uhs_card:
>> before
>>>> update: caps 0x407f020f, sd3_bus_mode = 3, sd_bus_speed = 3,
>>>> card->ocr = 0x40000.
>>>> [  115.168051] [5:    kworker/5:2:  207] [TEST] sd_update_bus_speed_mode:
>>>> caps 0x407f020f, sd3_bus_mode = 3, sd_bus_speed = 1, card->ocr =
>> 0x40000.
>>>> [  115.169176] [5:    kworker/5:2:  207] [TEST] sd_set_bus_speed_mode:
>>>> sd_bus_speed=1, timing=4, uhs_max_dtr=50000000, card->ocr=0x40000.
>>>>
>>>> TO-BE : TEST log with this commit
>>>> // resume : issue occurs : SDcard doesn't release busy for checking
>>>> 10 times
>>>> [ 1843.594805] [4:    kworker/4:5:21512] [TEST] mmc_sd_get_cid: ocr
>>>> 0x41040000(pocr 0x40000), retries 0.
>>>> [ 1843.594812] [4:    kworker/4:5:21512] mmc0: Skipping voltage switch
>>>> [ 1843.772555] [4:    kworker/4:5:21512] [TEST] mmc_sd_init_card: 1122:
>>>> caps=0x407f020f, sd3_bus_mode=0x1f, v18_fixup_failed false,
>>>> signal_voltage =0x0.
>>>> // no update sd3_bus_mode value
>>>> [ 1843.772563] [4:    kworker/4:5:21512] [TEST] mmc_sd_init_card: 1164:
>>>> switch hs.
>>>> // next resume : the SDcard initializes to SDR104
>>>> [ 1844.191295] [5:   kworker/5:93: 2282] [TEST] mmc_sd_init_card: 1122:
>>>> caps=0x407f020f, sd3_bus_mode=0x1f, v18_fixup_failed false,
>>>> signal_voltage =0x1.
>>>> [ 1844.191315] [5:   kworker/5:93: 2282] [TEST] mmc_sd_init_card: 1154:
>>>> rocr 0xc1ff8000, S18A, uhs.
>>>> [ 1844.192175] [5:   kworker/5:93: 2282] [TEST] mmc_sd_init_uhs_card:
>>>> before update: caps 0x407f020f, sd3_bus_mode = 0x1f, sd_bus_speed =
>>>> 3,
>>>> card->ocr = 0x40000.
>>>> [ 1844.192187] [5:   kworker/5:93: 2282] [TEST]
>> sd_update_bus_speed_mode:
>>>> caps 0x407f020f, sd3_bus_mode = 0x1f, sd_bus_speed = 3, card->ocr =
>>>> 0x40000.
>>>> [ 1844.198697] [5:   kworker/5:93: 2282] [TEST] sd_set_bus_speed_mode:
>>>> sd_bus_speed=3, timing=6, uhs_max_dtr=208000000, card->ocr=0x40000.
>>>>
>>>> Signed-off-by: Seunghui Lee <sh043.lee@samsung.com>
>>>> Tested-by: DooHyun Hwang <dh0421.hwang@samsung.com>
>>>> ---
>>>>  drivers/mmc/core/sd.c | 47
>>>> ++-----------------------------------------
>>>>  1 file changed, 2 insertions(+), 45 deletions(-)
>>>>
>>>> diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c index
>>>> cee4c0b59f43..4e3d39956185 100644
>>>> --- a/drivers/mmc/core/sd.c
>>>> +++ b/drivers/mmc/core/sd.c
>>>> @@ -1001,18 +1001,6 @@ unsigned mmc_sd_get_max_clock(struct mmc_card
>> *card)
>>>>  	return max_dtr;
>>>>  }
>>>>
>>>> -static bool mmc_sd_card_using_v18(struct mmc_card *card) -{
>>>> -	/*
>>>> -	 * According to the SD spec., the Bus Speed Mode (function group 1)
>>>> bits
>>>> -	 * 2 to 4 are zero if the card is initialized at 3.3V signal level.
>>>> Thus
>>>> -	 * they can be used to determine if the card has already switched
>>>> to
>>>> -	 * 1.8V signaling.
>>>> -	 */
>>>> -	return card->sw_caps.sd3_bus_mode &
>>>> -	       (SD_MODE_UHS_SDR50 | SD_MODE_UHS_SDR104 | SD_MODE_UHS_DDR50);
>>>> -}
>>>> -
>>>>  static int sd_write_ext_reg(struct mmc_card *card, u8 fno, u8 page,
>>>> u16 offset,
>>>>  			    u8 reg_data)
>>>>  {
>>>> @@ -1400,10 +1388,9 @@ static int mmc_sd_init_card(struct mmc_host
>>>> *host,
>>>> u32 ocr,
>>>>  	int err;
>>>>  	u32 cid[4];
>>>>  	u32 rocr = 0;
>>>> -	bool v18_fixup_failed = false;
>>>>
>>>>  	WARN_ON(!host->claimed);
>>>> -retry:
>>>> +
>>>>  	err = mmc_sd_get_cid(host, ocr, cid, &rocr);
>>>>  	if (err)
>>>>  		return err;
>>>> @@ -1472,36 +1459,6 @@ static int mmc_sd_init_card(struct mmc_host
>>>> *host,
>>>> u32 ocr,
>>>>  	if (err)
>>>>  		goto free_card;
>>>>
>>>> -	/*
>>>> -	 * If the card has not been power cycled, it may still be using
>>>> 1.8V
>>>> -	 * signaling. Detect that situation and try to initialize a UHS-I
>>>> (1.8V)
>>>> -	 * transfer mode.
>>>> -	 */
>>>> -	if (!v18_fixup_failed && !mmc_host_is_spi(host) &&
>>>> mmc_host_uhs(host) &&
>>>> -	    mmc_sd_card_using_v18(card) &&
>>>> -	    host->ios.signal_voltage != MMC_SIGNAL_VOLTAGE_180) {
>>>> -		/*
>>>> -		 * Re-read switch information in case it has changed since
>>>> -		 * oldcard was initialized.
>>>> -		 */
>>>> -		if (oldcard) {
>>>> -			err = mmc_read_switch(card);
>>>> -			if (err)
>>>> -				goto free_card;
>>>> -		}
>>>> -		if (mmc_sd_card_using_v18(card)) {
>>>> -			if (mmc_host_set_uhs_voltage(host) ||
>>>> -			    mmc_sd_init_uhs_card(card)) {
>>>> -				v18_fixup_failed = true;
>>>> -				mmc_power_cycle(host, ocr);
>>>> -				if (!oldcard)
>>>> -					mmc_remove_card(card);
>>>> -				goto retry;
>>>> -			}
>>>> -			goto done;
>>>> -		}
>>>> -	}
>>>> -
>>>>  	/* Initialization sequence for UHS-I cards */
>>>>  	if (rocr & SD_ROCR_S18A && mmc_host_uhs(host)) {
>>>>  		err = mmc_sd_init_uhs_card(card);
>>>> @@ -1566,7 +1523,7 @@ static int mmc_sd_init_card(struct mmc_host
>>>> *host,
>>>> u32 ocr,
>>>>  		err = -EINVAL;
>>>>  		goto free_card;
>>>>  	}
>>>> -done:
>>>> +
>>>>  	host->card = card;
>>>>  	return 0;
>>>>
>>>> --
>>>> 2.29.0
>>>
>>> Dear All,
>>>
>>> Please review this commit.
>>
>> I have started to look at it, but my time is limited at the moment.
>>
>> Note the original patch is 5 years old and fixes a real problem, so we
>> don't want to just throw it away.
>>
> 
> Dear Mr. hunter,
> 
> Could you check this with below patch?
> 
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/drivers/mmc/core/core.c?id=147186f531ae49c18b7a9091a2c40e83b3d95649
> 
> In the mmc_set_uhs_voltaga func(),
> once it occurs error, it has power_cycle except R1_ERROR with CMD11.
> So, When mmc_set_uhs_voltage() return error,
> host and card can't leave 1.8V voltage.
> 
> Regards,
> 
>>>
>>> Once the SDR104 SD card fails to switch voltage, there is no chance to
>>> work SDR104 bus speed again due to update sd3_bus_mode.
>>>
>>> To fix this regression issue, do not update sd3_bus_mode.
>>> And then it has the chance to work SDR104 again.
>>>
>>> AS-IS:
>>> voltage_switch fail -> mmc_read_switch() -> HS mode next system resume
>>> voltage switch success -> SDR25 mode
>>>
>>> TO-BE:
>>> Voltage switch fail -> HS mode
>>> Next system resume
>>> Voltage switch success -> SDR104 mode
>>>
>>> And plus, mmc_set_uhs_voltage() has power_cycle now.
>>> It means that if voltage switch fails, the card initializes 3.3V
>>> signal level.
>>>
>>> Regards,
>>> Seunghui Lee.
>>>
> 
> 

Does this help?

diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c
index cee4c0b59f43..1abe8af48bfc 100644
--- a/drivers/mmc/core/sd.c
+++ b/drivers/mmc/core/sd.c
@@ -949,15 +949,15 @@ int mmc_sd_setup_card(struct mmc_host *host, struct mmc_card *card,
 
 		/* Erase init depends on CSD and SSR */
 		mmc_init_erase(card);
-
-		/*
-		 * Fetch switch information from card.
-		 */
-		err = mmc_read_switch(card);
-		if (err)
-			return err;
 	}
 
+	/*
+	 * Fetch switch information from card.
+	 */
+	err = mmc_read_switch(card);
+	if (err)
+		return err;
+
 	/*
 	 * For SPI, enable CRC as appropriate.
 	 * This CRC enable is located AFTER the reading of the
이승희 Aug. 10, 2022, 4:24 a.m. UTC | #5
> -----Original Message-----
> From: Adrian Hunter <adrian.hunter@intel.com>
> Sent: Tuesday, August 9, 2022 2:37 PM
> To: Seunghui Lee <sh043.lee@samsung.com>; linux-mmc@vger.kernel.org
> Cc: 'DooHyun Hwang' <dh0421.hwang@samsung.com>
> Subject: Re: [PATCH] mmc: sd: Remove the patch that fix signal voltage
> when there is no power cycle
> 
> On 8/08/22 11:24, Seunghui Lee wrote:
> >> -----Original Message-----
> >> From: Adrian Hunter <adrian.hunter@intel.com>
> >> Sent: Tuesday, July 26, 2022 7:57 PM
> >> To: Seunghui Lee <sh043.lee@samsung.com>; linux-mmc@vger.kernel.org;
> >> adrian.hunter@intel.com
> >> Cc: 'DooHyun Hwang' <dh0421.hwang@samsung.com>
> >> Subject: Re: [PATCH] mmc: sd: Remove the patch that fix signal
> >> voltage when there is no power cycle
> >>
> >> On 26/07/22 05:56, Seunghui Lee wrote:
> >>>> -----Original Message-----
> >>>> From: Seunghui Lee <sh043.lee@samsung.com>
> >>>> Sent: Thursday, July 21, 2022 2:59 PM
> >>>> To: ulf.hansson@linaro.org; linux-mmc@vger.kernel.org;
> >>>> adrian.hunter@intel.com
> >>>> Cc: Seunghui Lee <sh043.lee@samsung.com>; DooHyun Hwang
> >>>> <dh0421.hwang@samsung.com>
> >>>> Subject: [PATCH] mmc: sd: Remove the patch that fix signal voltage
> >>>> when there is no power cycle
> >>>>
> >>>> At first, all error flow of mmc_set_uhs_voltage() has power cycle
> >>>> except R1_ERROR and no start_signal_voltage_switch() func pointer.
> >>>>
> >>>> There is the performance regression issue of SDR104 SD card from
> >>>> the market VOC. Normally, once a SDR104 SD card fails to switch
> >>>> voltage, it works HS mode.
> >>>> And then it initializes SDR104 mode after system resume or error
> >> handling.
> >>>>
> >>>> However, with below patch,
> >>>> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/
> >>>> co
> >>>> mmit/
> >>>> drivers/mmc/core/sd.c?id=6a11fc47f175c8d87018e89cb58e2d36c66534cb
> >>>> Once a SD card does, it initializes SDR25 mode forever after system
> >>>> resume or error handling(re-initialized).
> >>>> Host updates sd3_bus_mode by calling mmc_read_switch(), the value
> >>>> of sd3_bus_mode doesn't set for SDR104, SDR50 and DDR50 mode.
> >>>>
> >>>> So, if host doesn't update sd3_bus_mode, the SD card works SDR104
> >>>> mode after system resume or error-handling.
> >>>>
> >>>> Here is an example.
> >>>>
> >>>> AS-IS : test log
> >>>> // normal case : sd3_bus_mode = 0x1F, sd_bus_speed = SDR104, clock
> >> 208MHz
> >>>> [  111.907789] [1:    kworker/1:3:  772] [TEST] mmc_sd_init_card: 1119:
> >>>> caps=0x407f020f, sd3_bus_mode=0x1f, v18_fixup_failed false,
> >>>> signal_voltage =0x1.
> >>>> [  111.907824] [1:    kworker/1:3:  772] [TEST] mmc_sd_init_card: 1149:
> >> rocr
> >>>> 0xc1ff8000, S18A, uhs.
> >>>> [  111.908707] [1:    kworker/1:3:  772] [TEST]
> sd_update_bus_speed_mode:
> >>>> caps 0x407f020f, sd3_bus_mode = 0x1f, sd_bus_speed = 3, card->ocr =
> >>>> 0x40000.
> >>>> [  111.912484] [1:    kworker/1:3:  772] [TEST] sd_set_bus_speed_mode:
> >>>> sd_bus_speed=3, timing=6, uhs_max_dtr=208000000, card->ocr=0x40000.
> >>>> // resume : issue occurs : SDcard doesn't release busy for checking
> >>>> 10 times
> >>>> [  112.096550] [5:    kworker/5:2:  207] [TEST] mmc_sd_init_card: 1040:
> >>>> card->ocr 0x40000.
> >>>> [  112.096560] [5:    kworker/5:2:  207] [TEST] mmc_sd_get_cid: ocr
> >>>> 0x40000(pocr 0x40000), retries 10.
> >>>> ...
> >>>> [  114.531129] [5:    kworker/5:2:  207] [TEST] mmc_power_cycle.
> >>>> [  114.579500] [5:    kworker/5:2:  207] [TEST] mmc_sd_get_cid: ocr
> >>>> 0x41040000(pocr 0x40000), retries 0.
> >>>> [  114.579506] [5:    kworker/5:2:  207] mmc0: Skipping voltage switch
> >>>> [  114.757575] [5:    kworker/5:2:  207] [TEST] mmc_sd_init_card: 1119:
> >>>> caps=0x407f020f, sd3_bus_mode=0x1f, v18_fixup_failed false,
> >>>> signal_voltage =0x0.
> >>>> [  114.757583] [5:    kworker/5:2:  207] [TEST] mmc_sd_init_card: 1128:
> >>>> switch with oldcard.
> >>>> [  114.759742] [5:    kworker/5:2:  207] [TEST] mmc_read_switch:
> >> sd_switch
> >>>> ret 0, sd3_bus_mode=3.
> >>>> // sd3_bus_mode = 0x3 supports HS, SDR25 and SDR12
> >>>> [  114.759750] [5:    kworker/5:2:  207] [TEST] mmc_sd_init_card: 1157:
> >>>> switch hs.
> >>>> // next resume : the SDcard initializes to SDR25(HS)
> >>>> mode(sd_bus_speed = 1) by sd3_bus_mode setting with clk 50MHz
> >>>> [  114.968346] [5:    kworker/5:2:  207] [TEST] mmc_sd_init_card: 1040:
> >>>> card->ocr 0x40000.
> >>>> [  114.968359] [5:    kworker/5:2:  207] [TEST] mmc_sd_get_cid: ocr
> >>>> 0x40000(pocr 0x40000), retries 10.
> >>>> [  115.167346] [5:    kworker/5:2:  207] [TEST] mmc_sd_init_card: 1119:
> >>>> caps=0x407f020f, sd3_bus_mode=0x3, v18_fixup_failed false,
> >>>> signal_voltage =0x1.
> >>>> [  115.167366] [5:    kworker/5:2:  207] [TEST] mmc_sd_init_card: 1149:
> >> rocr
> >>>> 0xc1ff8000, S18A, uhs.
> >>>> [  115.168041] [5:    kworker/5:2:  207] [TEST] mmc_sd_init_uhs_card:
> >> before
> >>>> update: caps 0x407f020f, sd3_bus_mode = 3, sd_bus_speed = 3,
> >>>> card->ocr = 0x40000.
> >>>> [  115.168051] [5:    kworker/5:2:  207] [TEST]
> sd_update_bus_speed_mode:
> >>>> caps 0x407f020f, sd3_bus_mode = 3, sd_bus_speed = 1, card->ocr =
> >> 0x40000.
> >>>> [  115.169176] [5:    kworker/5:2:  207] [TEST] sd_set_bus_speed_mode:
> >>>> sd_bus_speed=1, timing=4, uhs_max_dtr=50000000, card->ocr=0x40000.
> >>>>
> >>>> TO-BE : TEST log with this commit
> >>>> // resume : issue occurs : SDcard doesn't release busy for checking
> >>>> 10 times
> >>>> [ 1843.594805] [4:    kworker/4:5:21512] [TEST] mmc_sd_get_cid: ocr
> >>>> 0x41040000(pocr 0x40000), retries 0.
> >>>> [ 1843.594812] [4:    kworker/4:5:21512] mmc0: Skipping voltage switch
> >>>> [ 1843.772555] [4:    kworker/4:5:21512] [TEST] mmc_sd_init_card: 1122:
> >>>> caps=0x407f020f, sd3_bus_mode=0x1f, v18_fixup_failed false,
> >>>> signal_voltage =0x0.
> >>>> // no update sd3_bus_mode value
> >>>> [ 1843.772563] [4:    kworker/4:5:21512] [TEST] mmc_sd_init_card: 1164:
> >>>> switch hs.
> >>>> // next resume : the SDcard initializes to SDR104
> >>>> [ 1844.191295] [5:   kworker/5:93: 2282] [TEST] mmc_sd_init_card:
> 1122:
> >>>> caps=0x407f020f, sd3_bus_mode=0x1f, v18_fixup_failed false,
> >>>> signal_voltage =0x1.
> >>>> [ 1844.191315] [5:   kworker/5:93: 2282] [TEST] mmc_sd_init_card:
> 1154:
> >>>> rocr 0xc1ff8000, S18A, uhs.
> >>>> [ 1844.192175] [5:   kworker/5:93: 2282] [TEST] mmc_sd_init_uhs_card:
> >>>> before update: caps 0x407f020f, sd3_bus_mode = 0x1f, sd_bus_speed =
> >>>> 3,
> >>>> card->ocr = 0x40000.
> >>>> [ 1844.192187] [5:   kworker/5:93: 2282] [TEST]
> >> sd_update_bus_speed_mode:
> >>>> caps 0x407f020f, sd3_bus_mode = 0x1f, sd_bus_speed = 3, card->ocr =
> >>>> 0x40000.
> >>>> [ 1844.198697] [5:   kworker/5:93: 2282] [TEST] sd_set_bus_speed_mode:
> >>>> sd_bus_speed=3, timing=6, uhs_max_dtr=208000000, card->ocr=0x40000.
> >>>>
> >>>> Signed-off-by: Seunghui Lee <sh043.lee@samsung.com>
> >>>> Tested-by: DooHyun Hwang <dh0421.hwang@samsung.com>
> >>>> ---
> >>>>  drivers/mmc/core/sd.c | 47
> >>>> ++-----------------------------------------
> >>>>  1 file changed, 2 insertions(+), 45 deletions(-)
> >>>>
> >>>> diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c index
> >>>> cee4c0b59f43..4e3d39956185 100644
> >>>> --- a/drivers/mmc/core/sd.c
> >>>> +++ b/drivers/mmc/core/sd.c
> >>>> @@ -1001,18 +1001,6 @@ unsigned mmc_sd_get_max_clock(struct
> >>>> mmc_card
> >> *card)
> >>>>  	return max_dtr;
> >>>>  }
> >>>>
> >>>> -static bool mmc_sd_card_using_v18(struct mmc_card *card) -{
> >>>> -	/*
> >>>> -	 * According to the SD spec., the Bus Speed Mode (function group 1)
> >>>> bits
> >>>> -	 * 2 to 4 are zero if the card is initialized at 3.3V signal level.
> >>>> Thus
> >>>> -	 * they can be used to determine if the card has already switched
> >>>> to
> >>>> -	 * 1.8V signaling.
> >>>> -	 */
> >>>> -	return card->sw_caps.sd3_bus_mode &
> >>>> -	       (SD_MODE_UHS_SDR50 | SD_MODE_UHS_SDR104 | SD_MODE_UHS_DDR50);
> >>>> -}
> >>>> -
> >>>>  static int sd_write_ext_reg(struct mmc_card *card, u8 fno, u8
> >>>> page,
> >>>> u16 offset,
> >>>>  			    u8 reg_data)
> >>>>  {
> >>>> @@ -1400,10 +1388,9 @@ static int mmc_sd_init_card(struct mmc_host
> >>>> *host,
> >>>> u32 ocr,
> >>>>  	int err;
> >>>>  	u32 cid[4];
> >>>>  	u32 rocr = 0;
> >>>> -	bool v18_fixup_failed = false;
> >>>>
> >>>>  	WARN_ON(!host->claimed);
> >>>> -retry:
> >>>> +
> >>>>  	err = mmc_sd_get_cid(host, ocr, cid, &rocr);
> >>>>  	if (err)
> >>>>  		return err;
> >>>> @@ -1472,36 +1459,6 @@ static int mmc_sd_init_card(struct mmc_host
> >>>> *host,
> >>>> u32 ocr,
> >>>>  	if (err)
> >>>>  		goto free_card;
> >>>>
> >>>> -	/*
> >>>> -	 * If the card has not been power cycled, it may still be using
> >>>> 1.8V
> >>>> -	 * signaling. Detect that situation and try to initialize a UHS-I
> >>>> (1.8V)
> >>>> -	 * transfer mode.
> >>>> -	 */
> >>>> -	if (!v18_fixup_failed && !mmc_host_is_spi(host) &&
> >>>> mmc_host_uhs(host) &&
> >>>> -	    mmc_sd_card_using_v18(card) &&
> >>>> -	    host->ios.signal_voltage != MMC_SIGNAL_VOLTAGE_180) {
> >>>> -		/*
> >>>> -		 * Re-read switch information in case it has changed since
> >>>> -		 * oldcard was initialized.
> >>>> -		 */
> >>>> -		if (oldcard) {
> >>>> -			err = mmc_read_switch(card);
> >>>> -			if (err)
> >>>> -				goto free_card;
> >>>> -		}
> >>>> -		if (mmc_sd_card_using_v18(card)) {
> >>>> -			if (mmc_host_set_uhs_voltage(host) ||
> >>>> -			    mmc_sd_init_uhs_card(card)) {
> >>>> -				v18_fixup_failed = true;
> >>>> -				mmc_power_cycle(host, ocr);
> >>>> -				if (!oldcard)
> >>>> -					mmc_remove_card(card);
> >>>> -				goto retry;
> >>>> -			}
> >>>> -			goto done;
> >>>> -		}
> >>>> -	}
> >>>> -
> >>>>  	/* Initialization sequence for UHS-I cards */
> >>>>  	if (rocr & SD_ROCR_S18A && mmc_host_uhs(host)) {
> >>>>  		err = mmc_sd_init_uhs_card(card); @@ -1566,7 +1523,7 @@
> static
> >>>> int mmc_sd_init_card(struct mmc_host *host,
> >>>> u32 ocr,
> >>>>  		err = -EINVAL;
> >>>>  		goto free_card;
> >>>>  	}
> >>>> -done:
> >>>> +
> >>>>  	host->card = card;
> >>>>  	return 0;
> >>>>
> >>>> --
> >>>> 2.29.0
> >>>
> >>> Dear All,
> >>>
> >>> Please review this commit.
> >>
> >> I have started to look at it, but my time is limited at the moment.
> >>
> >> Note the original patch is 5 years old and fixes a real problem, so
> >> we don't want to just throw it away.
> >>
> >
> > Dear Mr. hunter,
> >
> > Could you check this with below patch?
> >
> > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/com
> > mit/drivers/mmc/core/core.c?id=147186f531ae49c18b7a9091a2c40e83b3d9564
> > 9
> >
> > In the mmc_set_uhs_voltaga func(),
> > once it occurs error, it has power_cycle except R1_ERROR with CMD11.
> > So, When mmc_set_uhs_voltage() return error, host and card can't leave
> > 1.8V voltage.
> >
> > Regards,
> >
> >>>
> >>> Once the SDR104 SD card fails to switch voltage, there is no chance
> >>> to work SDR104 bus speed again due to update sd3_bus_mode.
> >>>
> >>> To fix this regression issue, do not update sd3_bus_mode.
> >>> And then it has the chance to work SDR104 again.
> >>>
> >>> AS-IS:
> >>> voltage_switch fail -> mmc_read_switch() -> HS mode next system
> >>> resume voltage switch success -> SDR25 mode
> >>>
> >>> TO-BE:
> >>> Voltage switch fail -> HS mode
> >>> Next system resume
> >>> Voltage switch success -> SDR104 mode
> >>>
> >>> And plus, mmc_set_uhs_voltage() has power_cycle now.
> >>> It means that if voltage switch fails, the card initializes 3.3V
> >>> signal level.
> >>>
> >>> Regards,
> >>> Seunghui Lee.
> >>>
> >
> >
> 
> Does this help?
> 
> diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c index
> cee4c0b59f43..1abe8af48bfc 100644
> --- a/drivers/mmc/core/sd.c
> +++ b/drivers/mmc/core/sd.c
> @@ -949,15 +949,15 @@ int mmc_sd_setup_card(struct mmc_host *host, struct
> mmc_card *card,
> 
>  		/* Erase init depends on CSD and SSR */
>  		mmc_init_erase(card);
> -
> -		/*
> -		 * Fetch switch information from card.
> -		 */
> -		err = mmc_read_switch(card);
> -		if (err)
> -			return err;
>  	}
> 
> +	/*
> +	 * Fetch switch information from card.
> +	 */
> +	err = mmc_read_switch(card);
> +	if (err)
> +		return err;
> +
>  	/*
>  	 * For SPI, enable CRC as appropriate.
>  	 * This CRC enable is located AFTER the reading of the

Dear Mr.Hunter,

Your suggestion works well :)
I've tested and verified the sd3_bus_mode's value updated.

So, May I update your suggestion as patch v2?
Or Would you like to your patch to contribute?

Regards,

Here is the test log.

[ 2347.726601] [4:   kworker/4:98: 2227] [TEST] mmc_sd_get_cid: ocr 0x41040000(pocr 0x40000), retries 0.
[ 2347.726608] [4:   kworker/4:98: 2227] mmc0: Skipping voltage switch
[ 2347.932495] [4:   kworker/4:98: 2227] [TEST] mmc_read_switch: sd_switch ret 0, sd3_bus_mode=0x3.
[ 2347.932508] [4:   kworker/4:98: 2227] [TEST] mmc_sd_init_card: 1116: caps=0x407f020f, sd3_bus_mode=0x3, v18_fixup_failed false, signal_voltage =0x0.
-> sd3_bus_mode is 0x3.
[ 2347.932514] [4:   kworker/4:98: 2227] [TEST] mmc_sd_init_card: 1154: switch hs.
[ 2347.936315] [4:   kworker/4:98: 2227] [TEST] mmc_sd_init_card: 1198: card->ocr 0x40000.

* next resume
[ 2348.156021] [0:    kworker/0:6:26086] [TEST] mmc_sd_init_card: 1037: card->ocr 0x40000.
[ 2348.156065] [0:    kworker/0:6:26086] [TEST] mmc_sd_get_cid: ocr 0x40000(pocr 0x40000), retries 10.
[ 2348.387214] [0:    kworker/0:6:26086] [TEST] mmc_read_switch: sd_switch ret 0, sd3_bus_mode=0x1f.
-> sd3_bus_mode is 0x1f
[ 2348.387253] [0:    kworker/0:6:26086] [TEST] mmc_sd_init_card: 1116: caps=0x407f020f, sd3_bus_mode=0x1f, v18_fixup_failed false, signal_voltage =0x1.
[ 2348.387273] [0:    kworker/0:6:26086] [TEST] mmc_sd_init_card: 1146: rocr 0xc1ff8000, S18A, uhs.
[ 2348.388399] [0:    kworker/0:6:26086] [TEST] mmc_sd_init_uhs_card: before update: caps 0x407f020f, sd3_bus_mode = 0x1f, sd_bus_speed = 3, card->ocr = 0x40000.
[ 2348.388427] [0:    kworker/0:6:26086] [TEST] sd_update_bus_speed_mode: caps 0x407f020f, sd3_bus_mode = 0x1f, sd_bus_speed = 3, card->ocr = 0x40000.
[ 2348.390614] [0:    kworker/0:6:26086] [TEST] sd_set_bus_speed_mode: sd_bus_speed=3, timing=6, uhs_max_dtr=208000000, card->ocr=0x40000.
[ 2348.393757] [0:    kworker/0:6:26086] [TEST] mmc_sd_init_card: 1198: card->ocr 0x40000.
Adrian Hunter Aug. 10, 2022, 1:06 p.m. UTC | #6
On 10/08/22 07:24, Seunghui Lee wrote:
>> -----Original Message-----
>> From: Adrian Hunter <adrian.hunter@intel.com>
>> Sent: Tuesday, August 9, 2022 2:37 PM
>> To: Seunghui Lee <sh043.lee@samsung.com>; linux-mmc@vger.kernel.org
>> Cc: 'DooHyun Hwang' <dh0421.hwang@samsung.com>
>> Subject: Re: [PATCH] mmc: sd: Remove the patch that fix signal voltage
>> when there is no power cycle
>>
>> On 8/08/22 11:24, Seunghui Lee wrote:
>>>> -----Original Message-----
>>>> From: Adrian Hunter <adrian.hunter@intel.com>
>>>> Sent: Tuesday, July 26, 2022 7:57 PM
>>>> To: Seunghui Lee <sh043.lee@samsung.com>; linux-mmc@vger.kernel.org;
>>>> adrian.hunter@intel.com
>>>> Cc: 'DooHyun Hwang' <dh0421.hwang@samsung.com>
>>>> Subject: Re: [PATCH] mmc: sd: Remove the patch that fix signal
>>>> voltage when there is no power cycle
>>>>
>>>> On 26/07/22 05:56, Seunghui Lee wrote:
>>>>>> -----Original Message-----
>>>>>> From: Seunghui Lee <sh043.lee@samsung.com>
>>>>>> Sent: Thursday, July 21, 2022 2:59 PM
>>>>>> To: ulf.hansson@linaro.org; linux-mmc@vger.kernel.org;
>>>>>> adrian.hunter@intel.com
>>>>>> Cc: Seunghui Lee <sh043.lee@samsung.com>; DooHyun Hwang
>>>>>> <dh0421.hwang@samsung.com>
>>>>>> Subject: [PATCH] mmc: sd: Remove the patch that fix signal voltage
>>>>>> when there is no power cycle
>>>>>>
>>>>>> At first, all error flow of mmc_set_uhs_voltage() has power cycle
>>>>>> except R1_ERROR and no start_signal_voltage_switch() func pointer.
>>>>>>
>>>>>> There is the performance regression issue of SDR104 SD card from
>>>>>> the market VOC. Normally, once a SDR104 SD card fails to switch
>>>>>> voltage, it works HS mode.
>>>>>> And then it initializes SDR104 mode after system resume or error
>>>> handling.
>>>>>>
>>>>>> However, with below patch,
>>>>>> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/
>>>>>> co
>>>>>> mmit/
>>>>>> drivers/mmc/core/sd.c?id=6a11fc47f175c8d87018e89cb58e2d36c66534cb
>>>>>> Once a SD card does, it initializes SDR25 mode forever after system
>>>>>> resume or error handling(re-initialized).
>>>>>> Host updates sd3_bus_mode by calling mmc_read_switch(), the value
>>>>>> of sd3_bus_mode doesn't set for SDR104, SDR50 and DDR50 mode.
>>>>>>
>>>>>> So, if host doesn't update sd3_bus_mode, the SD card works SDR104
>>>>>> mode after system resume or error-handling.
>>>>>>
>>>>>> Here is an example.
>>>>>>
>>>>>> AS-IS : test log
>>>>>> // normal case : sd3_bus_mode = 0x1F, sd_bus_speed = SDR104, clock
>>>> 208MHz
>>>>>> [  111.907789] [1:    kworker/1:3:  772] [TEST] mmc_sd_init_card: 1119:
>>>>>> caps=0x407f020f, sd3_bus_mode=0x1f, v18_fixup_failed false,
>>>>>> signal_voltage =0x1.
>>>>>> [  111.907824] [1:    kworker/1:3:  772] [TEST] mmc_sd_init_card: 1149:
>>>> rocr
>>>>>> 0xc1ff8000, S18A, uhs.
>>>>>> [  111.908707] [1:    kworker/1:3:  772] [TEST]
>> sd_update_bus_speed_mode:
>>>>>> caps 0x407f020f, sd3_bus_mode = 0x1f, sd_bus_speed = 3, card->ocr =
>>>>>> 0x40000.
>>>>>> [  111.912484] [1:    kworker/1:3:  772] [TEST] sd_set_bus_speed_mode:
>>>>>> sd_bus_speed=3, timing=6, uhs_max_dtr=208000000, card->ocr=0x40000.
>>>>>> // resume : issue occurs : SDcard doesn't release busy for checking
>>>>>> 10 times
>>>>>> [  112.096550] [5:    kworker/5:2:  207] [TEST] mmc_sd_init_card: 1040:
>>>>>> card->ocr 0x40000.
>>>>>> [  112.096560] [5:    kworker/5:2:  207] [TEST] mmc_sd_get_cid: ocr
>>>>>> 0x40000(pocr 0x40000), retries 10.
>>>>>> ...
>>>>>> [  114.531129] [5:    kworker/5:2:  207] [TEST] mmc_power_cycle.
>>>>>> [  114.579500] [5:    kworker/5:2:  207] [TEST] mmc_sd_get_cid: ocr
>>>>>> 0x41040000(pocr 0x40000), retries 0.
>>>>>> [  114.579506] [5:    kworker/5:2:  207] mmc0: Skipping voltage switch
>>>>>> [  114.757575] [5:    kworker/5:2:  207] [TEST] mmc_sd_init_card: 1119:
>>>>>> caps=0x407f020f, sd3_bus_mode=0x1f, v18_fixup_failed false,
>>>>>> signal_voltage =0x0.
>>>>>> [  114.757583] [5:    kworker/5:2:  207] [TEST] mmc_sd_init_card: 1128:
>>>>>> switch with oldcard.
>>>>>> [  114.759742] [5:    kworker/5:2:  207] [TEST] mmc_read_switch:
>>>> sd_switch
>>>>>> ret 0, sd3_bus_mode=3.
>>>>>> // sd3_bus_mode = 0x3 supports HS, SDR25 and SDR12
>>>>>> [  114.759750] [5:    kworker/5:2:  207] [TEST] mmc_sd_init_card: 1157:
>>>>>> switch hs.
>>>>>> // next resume : the SDcard initializes to SDR25(HS)
>>>>>> mode(sd_bus_speed = 1) by sd3_bus_mode setting with clk 50MHz
>>>>>> [  114.968346] [5:    kworker/5:2:  207] [TEST] mmc_sd_init_card: 1040:
>>>>>> card->ocr 0x40000.
>>>>>> [  114.968359] [5:    kworker/5:2:  207] [TEST] mmc_sd_get_cid: ocr
>>>>>> 0x40000(pocr 0x40000), retries 10.
>>>>>> [  115.167346] [5:    kworker/5:2:  207] [TEST] mmc_sd_init_card: 1119:
>>>>>> caps=0x407f020f, sd3_bus_mode=0x3, v18_fixup_failed false,
>>>>>> signal_voltage =0x1.
>>>>>> [  115.167366] [5:    kworker/5:2:  207] [TEST] mmc_sd_init_card: 1149:
>>>> rocr
>>>>>> 0xc1ff8000, S18A, uhs.
>>>>>> [  115.168041] [5:    kworker/5:2:  207] [TEST] mmc_sd_init_uhs_card:
>>>> before
>>>>>> update: caps 0x407f020f, sd3_bus_mode = 3, sd_bus_speed = 3,
>>>>>> card->ocr = 0x40000.
>>>>>> [  115.168051] [5:    kworker/5:2:  207] [TEST]
>> sd_update_bus_speed_mode:
>>>>>> caps 0x407f020f, sd3_bus_mode = 3, sd_bus_speed = 1, card->ocr =
>>>> 0x40000.
>>>>>> [  115.169176] [5:    kworker/5:2:  207] [TEST] sd_set_bus_speed_mode:
>>>>>> sd_bus_speed=1, timing=4, uhs_max_dtr=50000000, card->ocr=0x40000.
>>>>>>
>>>>>> TO-BE : TEST log with this commit
>>>>>> // resume : issue occurs : SDcard doesn't release busy for checking
>>>>>> 10 times
>>>>>> [ 1843.594805] [4:    kworker/4:5:21512] [TEST] mmc_sd_get_cid: ocr
>>>>>> 0x41040000(pocr 0x40000), retries 0.
>>>>>> [ 1843.594812] [4:    kworker/4:5:21512] mmc0: Skipping voltage switch
>>>>>> [ 1843.772555] [4:    kworker/4:5:21512] [TEST] mmc_sd_init_card: 1122:
>>>>>> caps=0x407f020f, sd3_bus_mode=0x1f, v18_fixup_failed false,
>>>>>> signal_voltage =0x0.
>>>>>> // no update sd3_bus_mode value
>>>>>> [ 1843.772563] [4:    kworker/4:5:21512] [TEST] mmc_sd_init_card: 1164:
>>>>>> switch hs.
>>>>>> // next resume : the SDcard initializes to SDR104
>>>>>> [ 1844.191295] [5:   kworker/5:93: 2282] [TEST] mmc_sd_init_card:
>> 1122:
>>>>>> caps=0x407f020f, sd3_bus_mode=0x1f, v18_fixup_failed false,
>>>>>> signal_voltage =0x1.
>>>>>> [ 1844.191315] [5:   kworker/5:93: 2282] [TEST] mmc_sd_init_card:
>> 1154:
>>>>>> rocr 0xc1ff8000, S18A, uhs.
>>>>>> [ 1844.192175] [5:   kworker/5:93: 2282] [TEST] mmc_sd_init_uhs_card:
>>>>>> before update: caps 0x407f020f, sd3_bus_mode = 0x1f, sd_bus_speed =
>>>>>> 3,
>>>>>> card->ocr = 0x40000.
>>>>>> [ 1844.192187] [5:   kworker/5:93: 2282] [TEST]
>>>> sd_update_bus_speed_mode:
>>>>>> caps 0x407f020f, sd3_bus_mode = 0x1f, sd_bus_speed = 3, card->ocr =
>>>>>> 0x40000.
>>>>>> [ 1844.198697] [5:   kworker/5:93: 2282] [TEST] sd_set_bus_speed_mode:
>>>>>> sd_bus_speed=3, timing=6, uhs_max_dtr=208000000, card->ocr=0x40000.
>>>>>>
>>>>>> Signed-off-by: Seunghui Lee <sh043.lee@samsung.com>
>>>>>> Tested-by: DooHyun Hwang <dh0421.hwang@samsung.com>
>>>>>> ---
>>>>>>  drivers/mmc/core/sd.c | 47
>>>>>> ++-----------------------------------------
>>>>>>  1 file changed, 2 insertions(+), 45 deletions(-)
>>>>>>
>>>>>> diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c index
>>>>>> cee4c0b59f43..4e3d39956185 100644
>>>>>> --- a/drivers/mmc/core/sd.c
>>>>>> +++ b/drivers/mmc/core/sd.c
>>>>>> @@ -1001,18 +1001,6 @@ unsigned mmc_sd_get_max_clock(struct
>>>>>> mmc_card
>>>> *card)
>>>>>>  	return max_dtr;
>>>>>>  }
>>>>>>
>>>>>> -static bool mmc_sd_card_using_v18(struct mmc_card *card) -{
>>>>>> -	/*
>>>>>> -	 * According to the SD spec., the Bus Speed Mode (function group 1)
>>>>>> bits
>>>>>> -	 * 2 to 4 are zero if the card is initialized at 3.3V signal level.
>>>>>> Thus
>>>>>> -	 * they can be used to determine if the card has already switched
>>>>>> to
>>>>>> -	 * 1.8V signaling.
>>>>>> -	 */
>>>>>> -	return card->sw_caps.sd3_bus_mode &
>>>>>> -	       (SD_MODE_UHS_SDR50 | SD_MODE_UHS_SDR104 | SD_MODE_UHS_DDR50);
>>>>>> -}
>>>>>> -
>>>>>>  static int sd_write_ext_reg(struct mmc_card *card, u8 fno, u8
>>>>>> page,
>>>>>> u16 offset,
>>>>>>  			    u8 reg_data)
>>>>>>  {
>>>>>> @@ -1400,10 +1388,9 @@ static int mmc_sd_init_card(struct mmc_host
>>>>>> *host,
>>>>>> u32 ocr,
>>>>>>  	int err;
>>>>>>  	u32 cid[4];
>>>>>>  	u32 rocr = 0;
>>>>>> -	bool v18_fixup_failed = false;
>>>>>>
>>>>>>  	WARN_ON(!host->claimed);
>>>>>> -retry:
>>>>>> +
>>>>>>  	err = mmc_sd_get_cid(host, ocr, cid, &rocr);
>>>>>>  	if (err)
>>>>>>  		return err;
>>>>>> @@ -1472,36 +1459,6 @@ static int mmc_sd_init_card(struct mmc_host
>>>>>> *host,
>>>>>> u32 ocr,
>>>>>>  	if (err)
>>>>>>  		goto free_card;
>>>>>>
>>>>>> -	/*
>>>>>> -	 * If the card has not been power cycled, it may still be using
>>>>>> 1.8V
>>>>>> -	 * signaling. Detect that situation and try to initialize a UHS-I
>>>>>> (1.8V)
>>>>>> -	 * transfer mode.
>>>>>> -	 */
>>>>>> -	if (!v18_fixup_failed && !mmc_host_is_spi(host) &&
>>>>>> mmc_host_uhs(host) &&
>>>>>> -	    mmc_sd_card_using_v18(card) &&
>>>>>> -	    host->ios.signal_voltage != MMC_SIGNAL_VOLTAGE_180) {
>>>>>> -		/*
>>>>>> -		 * Re-read switch information in case it has changed since
>>>>>> -		 * oldcard was initialized.
>>>>>> -		 */
>>>>>> -		if (oldcard) {
>>>>>> -			err = mmc_read_switch(card);
>>>>>> -			if (err)
>>>>>> -				goto free_card;
>>>>>> -		}
>>>>>> -		if (mmc_sd_card_using_v18(card)) {
>>>>>> -			if (mmc_host_set_uhs_voltage(host) ||
>>>>>> -			    mmc_sd_init_uhs_card(card)) {
>>>>>> -				v18_fixup_failed = true;
>>>>>> -				mmc_power_cycle(host, ocr);
>>>>>> -				if (!oldcard)
>>>>>> -					mmc_remove_card(card);
>>>>>> -				goto retry;
>>>>>> -			}
>>>>>> -			goto done;
>>>>>> -		}
>>>>>> -	}
>>>>>> -
>>>>>>  	/* Initialization sequence for UHS-I cards */
>>>>>>  	if (rocr & SD_ROCR_S18A && mmc_host_uhs(host)) {
>>>>>>  		err = mmc_sd_init_uhs_card(card); @@ -1566,7 +1523,7 @@
>> static
>>>>>> int mmc_sd_init_card(struct mmc_host *host,
>>>>>> u32 ocr,
>>>>>>  		err = -EINVAL;
>>>>>>  		goto free_card;
>>>>>>  	}
>>>>>> -done:
>>>>>> +
>>>>>>  	host->card = card;
>>>>>>  	return 0;
>>>>>>
>>>>>> --
>>>>>> 2.29.0
>>>>>
>>>>> Dear All,
>>>>>
>>>>> Please review this commit.
>>>>
>>>> I have started to look at it, but my time is limited at the moment.
>>>>
>>>> Note the original patch is 5 years old and fixes a real problem, so
>>>> we don't want to just throw it away.
>>>>
>>>
>>> Dear Mr. hunter,
>>>
>>> Could you check this with below patch?
>>>
>>> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/com
>>> mit/drivers/mmc/core/core.c?id=147186f531ae49c18b7a9091a2c40e83b3d9564
>>> 9
>>>
>>> In the mmc_set_uhs_voltaga func(),
>>> once it occurs error, it has power_cycle except R1_ERROR with CMD11.
>>> So, When mmc_set_uhs_voltage() return error, host and card can't leave
>>> 1.8V voltage.
>>>
>>> Regards,
>>>
>>>>>
>>>>> Once the SDR104 SD card fails to switch voltage, there is no chance
>>>>> to work SDR104 bus speed again due to update sd3_bus_mode.
>>>>>
>>>>> To fix this regression issue, do not update sd3_bus_mode.
>>>>> And then it has the chance to work SDR104 again.
>>>>>
>>>>> AS-IS:
>>>>> voltage_switch fail -> mmc_read_switch() -> HS mode next system
>>>>> resume voltage switch success -> SDR25 mode
>>>>>
>>>>> TO-BE:
>>>>> Voltage switch fail -> HS mode
>>>>> Next system resume
>>>>> Voltage switch success -> SDR104 mode
>>>>>
>>>>> And plus, mmc_set_uhs_voltage() has power_cycle now.
>>>>> It means that if voltage switch fails, the card initializes 3.3V
>>>>> signal level.
>>>>>
>>>>> Regards,
>>>>> Seunghui Lee.
>>>>>
>>>
>>>
>>
>> Does this help?
>>
>> diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c index
>> cee4c0b59f43..1abe8af48bfc 100644
>> --- a/drivers/mmc/core/sd.c
>> +++ b/drivers/mmc/core/sd.c
>> @@ -949,15 +949,15 @@ int mmc_sd_setup_card(struct mmc_host *host, struct
>> mmc_card *card,
>>
>>  		/* Erase init depends on CSD and SSR */
>>  		mmc_init_erase(card);
>> -
>> -		/*
>> -		 * Fetch switch information from card.
>> -		 */
>> -		err = mmc_read_switch(card);
>> -		if (err)
>> -			return err;
>>  	}
>>
>> +	/*
>> +	 * Fetch switch information from card.
>> +	 */
>> +	err = mmc_read_switch(card);
>> +	if (err)
>> +		return err;
>> +
>>  	/*
>>  	 * For SPI, enable CRC as appropriate.
>>  	 * This CRC enable is located AFTER the reading of the
> 
> Dear Mr.Hunter,
> 
> Your suggestion works well :)
> I've tested and verified the sd3_bus_mode's value updated.
> 
> So, May I update your suggestion as patch v2?
> Or Would you like to your patch to contribute?

I'll make a patch since there are related changes needed
and I would like to do some additional testing.

> 
> Regards,
> 
> Here is the test log.
> 
> [ 2347.726601] [4:   kworker/4:98: 2227] [TEST] mmc_sd_get_cid: ocr 0x41040000(pocr 0x40000), retries 0.
> [ 2347.726608] [4:   kworker/4:98: 2227] mmc0: Skipping voltage switch
> [ 2347.932495] [4:   kworker/4:98: 2227] [TEST] mmc_read_switch: sd_switch ret 0, sd3_bus_mode=0x3.
> [ 2347.932508] [4:   kworker/4:98: 2227] [TEST] mmc_sd_init_card: 1116: caps=0x407f020f, sd3_bus_mode=0x3, v18_fixup_failed false, signal_voltage =0x0.
> -> sd3_bus_mode is 0x3.
> [ 2347.932514] [4:   kworker/4:98: 2227] [TEST] mmc_sd_init_card: 1154: switch hs.
> [ 2347.936315] [4:   kworker/4:98: 2227] [TEST] mmc_sd_init_card: 1198: card->ocr 0x40000.
> 
> * next resume
> [ 2348.156021] [0:    kworker/0:6:26086] [TEST] mmc_sd_init_card: 1037: card->ocr 0x40000.
> [ 2348.156065] [0:    kworker/0:6:26086] [TEST] mmc_sd_get_cid: ocr 0x40000(pocr 0x40000), retries 10.
> [ 2348.387214] [0:    kworker/0:6:26086] [TEST] mmc_read_switch: sd_switch ret 0, sd3_bus_mode=0x1f.
> -> sd3_bus_mode is 0x1f
> [ 2348.387253] [0:    kworker/0:6:26086] [TEST] mmc_sd_init_card: 1116: caps=0x407f020f, sd3_bus_mode=0x1f, v18_fixup_failed false, signal_voltage =0x1.
> [ 2348.387273] [0:    kworker/0:6:26086] [TEST] mmc_sd_init_card: 1146: rocr 0xc1ff8000, S18A, uhs.
> [ 2348.388399] [0:    kworker/0:6:26086] [TEST] mmc_sd_init_uhs_card: before update: caps 0x407f020f, sd3_bus_mode = 0x1f, sd_bus_speed = 3, card->ocr = 0x40000.
> [ 2348.388427] [0:    kworker/0:6:26086] [TEST] sd_update_bus_speed_mode: caps 0x407f020f, sd3_bus_mode = 0x1f, sd_bus_speed = 3, card->ocr = 0x40000.
> [ 2348.390614] [0:    kworker/0:6:26086] [TEST] sd_set_bus_speed_mode: sd_bus_speed=3, timing=6, uhs_max_dtr=208000000, card->ocr=0x40000.
> [ 2348.393757] [0:    kworker/0:6:26086] [TEST] mmc_sd_init_card: 1198: card->ocr 0x40000.
>
diff mbox series

Patch

diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c
index cee4c0b59f43..4e3d39956185 100644
--- a/drivers/mmc/core/sd.c
+++ b/drivers/mmc/core/sd.c
@@ -1001,18 +1001,6 @@  unsigned mmc_sd_get_max_clock(struct mmc_card *card)
 	return max_dtr;
 }
 
-static bool mmc_sd_card_using_v18(struct mmc_card *card)
-{
-	/*
-	 * According to the SD spec., the Bus Speed Mode (function group 1) bits
-	 * 2 to 4 are zero if the card is initialized at 3.3V signal level. Thus
-	 * they can be used to determine if the card has already switched to
-	 * 1.8V signaling.
-	 */
-	return card->sw_caps.sd3_bus_mode &
-	       (SD_MODE_UHS_SDR50 | SD_MODE_UHS_SDR104 | SD_MODE_UHS_DDR50);
-}
-
 static int sd_write_ext_reg(struct mmc_card *card, u8 fno, u8 page, u16 offset,
 			    u8 reg_data)
 {
@@ -1400,10 +1388,9 @@  static int mmc_sd_init_card(struct mmc_host *host, u32 ocr,
 	int err;
 	u32 cid[4];
 	u32 rocr = 0;
-	bool v18_fixup_failed = false;
 
 	WARN_ON(!host->claimed);
-retry:
+
 	err = mmc_sd_get_cid(host, ocr, cid, &rocr);
 	if (err)
 		return err;
@@ -1472,36 +1459,6 @@  static int mmc_sd_init_card(struct mmc_host *host, u32 ocr,
 	if (err)
 		goto free_card;
 
-	/*
-	 * If the card has not been power cycled, it may still be using 1.8V
-	 * signaling. Detect that situation and try to initialize a UHS-I (1.8V)
-	 * transfer mode.
-	 */
-	if (!v18_fixup_failed && !mmc_host_is_spi(host) && mmc_host_uhs(host) &&
-	    mmc_sd_card_using_v18(card) &&
-	    host->ios.signal_voltage != MMC_SIGNAL_VOLTAGE_180) {
-		/*
-		 * Re-read switch information in case it has changed since
-		 * oldcard was initialized.
-		 */
-		if (oldcard) {
-			err = mmc_read_switch(card);
-			if (err)
-				goto free_card;
-		}
-		if (mmc_sd_card_using_v18(card)) {
-			if (mmc_host_set_uhs_voltage(host) ||
-			    mmc_sd_init_uhs_card(card)) {
-				v18_fixup_failed = true;
-				mmc_power_cycle(host, ocr);
-				if (!oldcard)
-					mmc_remove_card(card);
-				goto retry;
-			}
-			goto done;
-		}
-	}
-
 	/* Initialization sequence for UHS-I cards */
 	if (rocr & SD_ROCR_S18A && mmc_host_uhs(host)) {
 		err = mmc_sd_init_uhs_card(card);
@@ -1566,7 +1523,7 @@  static int mmc_sd_init_card(struct mmc_host *host, u32 ocr,
 		err = -EINVAL;
 		goto free_card;
 	}
-done:
+
 	host->card = card;
 	return 0;