| Message ID | fb7cda69c5c244dfa579229ee2f0da83@realtek.com |
|---|---|
| State | New |
| Headers | show |
| Series | mmc: rtsx: add 74 Clocks in power on flow | expand |
On Tue, Feb 22, 2022 at 07:27:52AM +0000, Ricky WU wrote: > After 1ms stabilizing the voltage time > add "Host provides at least 74 Clocks > before issuing first command" that is > spec definition You do have 72 columns to use here, no need to wrap this so tightly. > > Signed-off-by: Ricky Wu <ricky_wu@realtek.com> > --- > drivers/mmc/host/rtsx_pci_sdmmc.c | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/drivers/mmc/host/rtsx_pci_sdmmc.c b/drivers/mmc/host/rtsx_pci_sdmmc.c > index 2a3f14afe9f8..e016d720e453 100644 > --- a/drivers/mmc/host/rtsx_pci_sdmmc.c > +++ b/drivers/mmc/host/rtsx_pci_sdmmc.c > @@ -940,10 +940,17 @@ static int sd_power_on(struct realtek_pci_sdmmc *host) > if (err < 0) > return err; > > + mdelay(1); What is this delay for? thanks, greg k-h
On Tue, Feb 22, 2022 at 08:48:30AM +0000, Ricky WU wrote: > > -----Original Message----- > > From: gregkh@linuxfoundation.org <gregkh@linuxfoundation.org> > > Sent: Tuesday, February 22, 2022 3:42 PM > > To: Ricky WU <ricky_wu@realtek.com> > > Cc: ulf.hansson@linaro.org; kai.heng.feng@canonical.com; > > tommyhebb@gmail.com; linux-mmc@vger.kernel.org; > > linux-kernel@vger.kernel.org > > Subject: Re: [PATCH] mmc: rtsx: add 74 Clocks in power on flow > > > > On Tue, Feb 22, 2022 at 07:27:52AM +0000, Ricky WU wrote: > > > After 1ms stabilizing the voltage time add "Host provides at least 74 > > > Clocks before issuing first command" that is spec definition > > > > You do have 72 columns to use here, no need to wrap this so tightly. > > > > Ok... > so I need to have next patch to fix this format? Please do, because: > > > > > > > Signed-off-by: Ricky Wu <ricky_wu@realtek.com> > > > --- > > > drivers/mmc/host/rtsx_pci_sdmmc.c | 7 +++++++ > > > 1 file changed, 7 insertions(+) > > > > > > diff --git a/drivers/mmc/host/rtsx_pci_sdmmc.c > > > b/drivers/mmc/host/rtsx_pci_sdmmc.c > > > index 2a3f14afe9f8..e016d720e453 100644 > > > --- a/drivers/mmc/host/rtsx_pci_sdmmc.c > > > +++ b/drivers/mmc/host/rtsx_pci_sdmmc.c > > > @@ -940,10 +940,17 @@ static int sd_power_on(struct realtek_pci_sdmmc > > *host) > > > if (err < 0) > > > return err; > > > > > > + mdelay(1); > > > > What is this delay for? > > > > Spec definition, need to wait 1ms for voltage stable > and below mdelay(5) is our device send 74 Clocks time Clock cycles and mdelay() are not going to always stay the same, right? I really have no idea what "74 clocks time" means, is this some specific timing value for this hardware? What is the units? This needs to be documented better in both the changelog and in the code. thanks, greg k-h
On Tue, Feb 22, 2022 at 12:31:10PM +0000, Ricky WU wrote: > > -----Original Message----- > > From: gregkh@linuxfoundation.org <gregkh@linuxfoundation.org> > > Sent: Tuesday, February 22, 2022 4:59 PM > > To: Ricky WU <ricky_wu@realtek.com> > > Cc: ulf.hansson@linaro.org; kai.heng.feng@canonical.com; > > tommyhebb@gmail.com; linux-mmc@vger.kernel.org; > > linux-kernel@vger.kernel.org > > Subject: Re: [PATCH] mmc: rtsx: add 74 Clocks in power on flow > > > > On Tue, Feb 22, 2022 at 08:48:30AM +0000, Ricky WU wrote: > > > > -----Original Message----- > > > > From: gregkh@linuxfoundation.org <gregkh@linuxfoundation.org> > > > > Sent: Tuesday, February 22, 2022 3:42 PM > > > > To: Ricky WU <ricky_wu@realtek.com> > > > > Cc: ulf.hansson@linaro.org; kai.heng.feng@canonical.com; > > > > tommyhebb@gmail.com; linux-mmc@vger.kernel.org; > > > > linux-kernel@vger.kernel.org > > > > Subject: Re: [PATCH] mmc: rtsx: add 74 Clocks in power on flow > > > > > > > > On Tue, Feb 22, 2022 at 07:27:52AM +0000, Ricky WU wrote: > > > > > After 1ms stabilizing the voltage time add "Host provides at least > > > > > 74 Clocks before issuing first command" that is spec definition > > > > > > > > You do have 72 columns to use here, no need to wrap this so tightly. > > > > > > > > > > Ok... > > > so I need to have next patch to fix this format? > > > > Please do, because: > > > > > > > > > > > > > > > Signed-off-by: Ricky Wu <ricky_wu@realtek.com> > > > > > --- > > > > > drivers/mmc/host/rtsx_pci_sdmmc.c | 7 +++++++ > > > > > 1 file changed, 7 insertions(+) > > > > > > > > > > diff --git a/drivers/mmc/host/rtsx_pci_sdmmc.c > > > > > b/drivers/mmc/host/rtsx_pci_sdmmc.c > > > > > index 2a3f14afe9f8..e016d720e453 100644 > > > > > --- a/drivers/mmc/host/rtsx_pci_sdmmc.c > > > > > +++ b/drivers/mmc/host/rtsx_pci_sdmmc.c > > > > > @@ -940,10 +940,17 @@ static int sd_power_on(struct > > > > > realtek_pci_sdmmc > > > > *host) > > > > > if (err < 0) > > > > > return err; > > > > > > > > > > + mdelay(1); > > > > > > > > What is this delay for? > > > > > > > > > > Spec definition, need to wait 1ms for voltage stable and below > > > mdelay(5) is our device send 74 Clocks time > > > > Clock cycles and mdelay() are not going to always stay the same, right? > > > > I really have no idea what "74 clocks time" means, is this some specific timing > > value for this hardware? What is the units? This needs to be documented > > better in both the changelog and in the code. > > > > thanks, > > > > Please ref: https://www.sdcard.org/downloads/pls/ Version8 I can not download those specifications according to the license that they ask me to abide by. > And see the 6.4.1.2 Power Up Time of Host Figure 6-5: Power Up Diagram of Host > mdelay(1) corresponds to Stable supply voltage > mdelay(5) corresponds to Host provides at least 74 Clocks before issuing first command > our device need 5ms to issue 74 Clocks What is a "clock"? The kernel works with time units, how does "5" equal to 74? thanks, greg k-h
> -----Original Message----- > From: gregkh@linuxfoundation.org <gregkh@linuxfoundation.org> > Sent: Tuesday, February 22, 2022 10:18 PM > To: Ricky WU <ricky_wu@realtek.com> > Cc: ulf.hansson@linaro.org; kai.heng.feng@canonical.com; > tommyhebb@gmail.com; linux-mmc@vger.kernel.org; > linux-kernel@vger.kernel.org > Subject: Re: [PATCH] mmc: rtsx: add 74 Clocks in power on flow > > On Tue, Feb 22, 2022 at 12:31:10PM +0000, Ricky WU wrote: > > > -----Original Message----- > > > From: gregkh@linuxfoundation.org <gregkh@linuxfoundation.org> > > > Sent: Tuesday, February 22, 2022 4:59 PM > > > To: Ricky WU <ricky_wu@realtek.com> > > > Cc: ulf.hansson@linaro.org; kai.heng.feng@canonical.com; > > > tommyhebb@gmail.com; linux-mmc@vger.kernel.org; > > > linux-kernel@vger.kernel.org > > > Subject: Re: [PATCH] mmc: rtsx: add 74 Clocks in power on flow > > > > > > On Tue, Feb 22, 2022 at 08:48:30AM +0000, Ricky WU wrote: > > > > > -----Original Message----- > > > > > From: gregkh@linuxfoundation.org <gregkh@linuxfoundation.org> > > > > > Sent: Tuesday, February 22, 2022 3:42 PM > > > > > To: Ricky WU <ricky_wu@realtek.com> > > > > > Cc: ulf.hansson@linaro.org; kai.heng.feng@canonical.com; > > > > > tommyhebb@gmail.com; linux-mmc@vger.kernel.org; > > > > > linux-kernel@vger.kernel.org > > > > > Subject: Re: [PATCH] mmc: rtsx: add 74 Clocks in power on flow > > > > > > > > > > On Tue, Feb 22, 2022 at 07:27:52AM +0000, Ricky WU wrote: > > > > > > After 1ms stabilizing the voltage time add "Host provides at > > > > > > least > > > > > > 74 Clocks before issuing first command" that is spec > > > > > > definition > > > > > > > > > > You do have 72 columns to use here, no need to wrap this so tightly. > > > > > > > > > > > > > Ok... > > > > so I need to have next patch to fix this format? > > > > > > Please do, because: > > > > > > > > > > > > > > > > > > > Signed-off-by: Ricky Wu <ricky_wu@realtek.com> > > > > > > --- > > > > > > drivers/mmc/host/rtsx_pci_sdmmc.c | 7 +++++++ > > > > > > 1 file changed, 7 insertions(+) > > > > > > > > > > > > diff --git a/drivers/mmc/host/rtsx_pci_sdmmc.c > > > > > > b/drivers/mmc/host/rtsx_pci_sdmmc.c > > > > > > index 2a3f14afe9f8..e016d720e453 100644 > > > > > > --- a/drivers/mmc/host/rtsx_pci_sdmmc.c > > > > > > +++ b/drivers/mmc/host/rtsx_pci_sdmmc.c > > > > > > @@ -940,10 +940,17 @@ static int sd_power_on(struct > > > > > > realtek_pci_sdmmc > > > > > *host) > > > > > > if (err < 0) > > > > > > return err; > > > > > > > > > > > > + mdelay(1); > > > > > > > > > > What is this delay for? > > > > > > > > > > > > > Spec definition, need to wait 1ms for voltage stable and below > > > > mdelay(5) is our device send 74 Clocks time > > > > > > Clock cycles and mdelay() are not going to always stay the same, right? > > > > > > I really have no idea what "74 clocks time" means, is this some > > > specific timing value for this hardware? What is the units? This > > > needs to be documented better in both the changelog and in the code. > > > > > > thanks, > > > > > > > Please ref: https://www.sdcard.org/downloads/pls/ Version8 > > I can not download those specifications according to the license that they ask > me to abide by. > > > And see the 6.4.1.2 Power Up Time of Host Figure 6-5: Power Up Diagram > > of Host > > mdelay(1) corresponds to Stable supply voltage > > mdelay(5) corresponds to Host provides at least 74 Clocks before > > issuing first command our device need 5ms to issue 74 Clocks > > What is a "clock"? The kernel works with time units, how does "5" equal to > 74? > spec original is "Host provides at least 74 Clocks before issuing first command" Let me clarify it, 74 Clocks means 74 clock signals, our Card Reader need to issue more than 74 Clock signals to Card before first command So mdelay(5) , our device will keep issue signal to card in this 5ms make sure over 74 > thanks, > > greg k-h > ------Please consider the environment before printing this e-mail.
On Tue, 22 Feb 2022 at 08:28, Ricky WU <ricky_wu@realtek.com> wrote: > > After 1ms stabilizing the voltage time > add "Host provides at least 74 Clocks > before issuing first command" that is > spec definition > > Signed-off-by: Ricky Wu <ricky_wu@realtek.com> > --- > drivers/mmc/host/rtsx_pci_sdmmc.c | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/drivers/mmc/host/rtsx_pci_sdmmc.c b/drivers/mmc/host/rtsx_pci_sdmmc.c > index 2a3f14afe9f8..e016d720e453 100644 > --- a/drivers/mmc/host/rtsx_pci_sdmmc.c > +++ b/drivers/mmc/host/rtsx_pci_sdmmc.c > @@ -940,10 +940,17 @@ static int sd_power_on(struct realtek_pci_sdmmc *host) > if (err < 0) > return err; > > + mdelay(1); > + > err = rtsx_pci_write_register(pcr, CARD_OE, SD_OUTPUT_EN, SD_OUTPUT_EN); > if (err < 0) > return err; > > + /* send init 74 clocks */ > + rtsx_pci_write_register(pcr, SD_BUS_STAT, SD_CLK_TOGGLE_EN, SD_CLK_TOGGLE_EN); > + mdelay(5); > + rtsx_pci_write_register(pcr, SD_BUS_STAT, SD_CLK_TOGGLE_EN, 0); > + > if (PCI_PID(pcr) == PID_5261) { > /* > * If test mode is set switch to SD Express mandatorily, As you probably are aware of, the mmc core uses three power states (MMC_POWER_ON, MMC_POWER_UP and MMC_POWER_OFF) to manage the initialization, while it invokes the ->set_ios() callback for the mmc host driver. During these steps the core also tries to manage the different delays that are needed according to the eMMC/SD specs. You may have a look at mmc_power_up() in drivers/mmc/core/core.c. In the rtsx case, MMC_POWER_ON and MMC_POWER_UP are treated as one single step. Moreover, it has turned out that some mmc HWs are actually controlling these delays during the initialization themselves, which makes the delays in the core superfluous. Therefore we have made the delays configurable for host drivers. For DT based platforms, we have the DT property "post-power-on-delay-ms" and for others, it's perfectly fine to update host->power_delay_ms before calling mmc_add_host(). Would it be possible to take advantage of the above "features" from the core, to avoid hard coded and superfluous delays? Kind regards Uffe
>> Can we get 1f311c94aabdb419c28e3147bcc8ab89269f1a7e merged into the stable tree? > >Which stable branches do you want this added to? > >thanks, > >greg k-h
On Mon, 9 May 2022 at 12:12, Christian Löhle <CLoehle@hyperstone.com> wrote: > > >> Can we get 1f311c94aabdb419c28e3147bcc8ab89269f1a7e merged into the stable tree? > > > >Which stable branches do you want this added to? > > > >thanks, > > > >greg k-h > > From what I can tell the issue is present since the addition of the driver in ff984e57d36e8 > So I would suggest adding them to all? Maybe Ricky and Ulf could comment? That seems correct. Although, it's likely that 1f311c94aabd doesn't apply to older stable trees, but I guess we can try and see how it goes. Perhaps an even better option is that you submit a backported patch to Greg for those stable kernels you want it to be applied to. Kind regards Uffe
diff --git a/drivers/mmc/host/rtsx_pci_sdmmc.c b/drivers/mmc/host/rtsx_pci_sdmmc.c index 2a3f14afe9f8..e016d720e453 100644 --- a/drivers/mmc/host/rtsx_pci_sdmmc.c +++ b/drivers/mmc/host/rtsx_pci_sdmmc.c @@ -940,10 +940,17 @@ static int sd_power_on(struct realtek_pci_sdmmc *host) if (err < 0) return err; + mdelay(1); + err = rtsx_pci_write_register(pcr, CARD_OE, SD_OUTPUT_EN, SD_OUTPUT_EN); if (err < 0) return err; + /* send init 74 clocks */ + rtsx_pci_write_register(pcr, SD_BUS_STAT, SD_CLK_TOGGLE_EN, SD_CLK_TOGGLE_EN); + mdelay(5); + rtsx_pci_write_register(pcr, SD_BUS_STAT, SD_CLK_TOGGLE_EN, 0); + if (PCI_PID(pcr) == PID_5261) { /* * If test mode is set switch to SD Express mandatorily,
After 1ms stabilizing the voltage time add "Host provides at least 74 Clocks before issuing first command" that is spec definition Signed-off-by: Ricky Wu <ricky_wu@realtek.com> --- drivers/mmc/host/rtsx_pci_sdmmc.c | 7 +++++++ 1 file changed, 7 insertions(+)