| Message ID | 1430816089-8857-1-git-send-email-zhangfei.gao@linaro.org |
|---|---|
| State | New |
| Headers | show |
On 6 May 2015 at 08:36, Jaehoon Chung <jh80.chung@samsung.com> wrote: > Hi, Zhangfei. > > If you want to check it, use the "broken-cd" and "non-removable" properties into dt-file. > Did you use them? Yes. "broken-cd" can work, but mmc_rescan keeps running. "non-removable" does NOT work, which should be used for emmc. Since dw_mci_get_cd only checks DW_MCI_QUIRK_BROKEN_CARD_DETECTION, so only checks "broken-cd" but not check "non-removable" Thanks -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 05/06/2015 09:26 AM, Jaehoon Chung wrote: > Hi, > > On 05/06/2015 10:14 AM, Zhangfei Gao wrote: >> On 6 May 2015 at 08:36, Jaehoon Chung <jh80.chung@samsung.com> wrote: >>> Hi, Zhangfei. >>> >>> If you want to check it, use the "broken-cd" and "non-removable" properties into dt-file. >>> Did you use them? >> >> Yes. >> "broken-cd" can work, but mmc_rescan keeps running. >> "non-removable" does NOT work, which should be used for emmc. >> Since dw_mci_get_cd only checks DW_MCI_QUIRK_BROKEN_CARD_DETECTION, so >> only checks "broken-cd" but not check "non-removable" > > Did you use the usage like the below.. > > dwmmc0 { > non-removable; > broken-cd; > }; non-removable and broken-cd should be used only one. Documentation/devicetree/bindings/mmc/mmc.txt Card detection: If no property below is supplied, host native card detect is used. Only one of the properties in this section should be supplied: - broken-cd: There is no card detection available; polling must be used. - cd-gpios: Specify GPIOs for card detection, see gpio binding - non-removable: non-removable slot (like eMMC); assume always present. work dwmmc0 { broken-cd; }; NOT work dwmmc0 { non-removable; }; Thanks -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 05/06/2015 09:39 AM, Jaehoon Chung wrote: > Hi, > > On 05/06/2015 10:33 AM, zhangfei wrote: >> >> >> On 05/06/2015 09:26 AM, Jaehoon Chung wrote: >>> Hi, >>> >>> On 05/06/2015 10:14 AM, Zhangfei Gao wrote: >>>> On 6 May 2015 at 08:36, Jaehoon Chung <jh80.chung@samsung.com> wrote: >>>>> Hi, Zhangfei. >>>>> >>>>> If you want to check it, use the "broken-cd" and "non-removable" properties into dt-file. >>>>> Did you use them? >>>> >>>> Yes. >>>> "broken-cd" can work, but mmc_rescan keeps running. >>>> "non-removable" does NOT work, which should be used for emmc. >>>> Since dw_mci_get_cd only checks DW_MCI_QUIRK_BROKEN_CARD_DETECTION, so >>>> only checks "broken-cd" but not check "non-removable" >>> >>> Did you use the usage like the below.. >>> >>> dwmmc0 { >>> non-removable; >>> broken-cd; >>> }; >> >> non-removable and broken-cd should be used only one. > > Did you check the code? > If non-removable is set, broken-cd should be discarded. > > I think that the below usage is not "must not". Sorry, not understand. Just want to use non-removable for emmc, and find it does not work. Use broken-cd for emmc is not correct. > > Best Regards, > Jaehoon Chung > >> >> Documentation/devicetree/bindings/mmc/mmc.txt >> Card detection: >> If no property below is supplied, host native card detect is used. >> Only one of the properties in this section should be supplied: >> - broken-cd: There is no card detection available; polling must be used. >> - cd-gpios: Specify GPIOs for card detection, see gpio binding >> - non-removable: non-removable slot (like eMMC); assume always present. >> >> work >> dwmmc0 { >> broken-cd; >> }; >> >> NOT work >> dwmmc0 { >> non-removable; >> }; >> >> Thanks >> > -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 05/06/2015 09:39 AM, Jaehoon Chung wrote: > Hi, > > On 05/06/2015 10:33 AM, zhangfei wrote: >> >> >> On 05/06/2015 09:26 AM, Jaehoon Chung wrote: >>> Hi, >>> >>> On 05/06/2015 10:14 AM, Zhangfei Gao wrote: >>>> On 6 May 2015 at 08:36, Jaehoon Chung <jh80.chung@samsung.com> wrote: >>>>> Hi, Zhangfei. >>>>> >>>>> If you want to check it, use the "broken-cd" and "non-removable" properties into dt-file. >>>>> Did you use them? >>>> >>>> Yes. >>>> "broken-cd" can work, but mmc_rescan keeps running. >>>> "non-removable" does NOT work, which should be used for emmc. >>>> Since dw_mci_get_cd only checks DW_MCI_QUIRK_BROKEN_CARD_DETECTION, so >>>> only checks "broken-cd" but not check "non-removable" >>> >>> Did you use the usage like the below.. >>> >>> dwmmc0 { >>> non-removable; >>> broken-cd; >>> }; >> >> non-removable and broken-cd should be used only one. > > Did you check the code? > If non-removable is set, broken-cd should be discarded. > > I think that the below usage is not "must not". I understand you meaning, you suggest >>> dwmmc0 { >>> non-removable; >>> broken-cd; >>> }; drivers/mmc/host/dw_mmc.c checks broken-cd, while mmc_of_parse checks non-removable. Yes, it works. But is it a workaround? and a little tricky. It costs me some time to find why non-removable does not work, someone else may meet the same issue. It does not align with Documentation/devicetree/bindings/mmc/mmc.txt, which is the guideline to write dts. And see drivers/mmc/host/sdhci.c: sdhci_do_get_cd, it also checks both. Thanks > > Best Regards, > Jaehoon Chung > >> >> Documentation/devicetree/bindings/mmc/mmc.txt >> Card detection: >> If no property below is supplied, host native card detect is used. >> Only one of the properties in this section should be supplied: >> - broken-cd: There is no card detection available; polling must be used. >> - cd-gpios: Specify GPIOs for card detection, see gpio binding >> - non-removable: non-removable slot (like eMMC); assume always present. >> >> work >> dwmmc0 { >> broken-cd; >> }; >> >> NOT work >> dwmmc0 { >> non-removable; >> }; >> >> Thanks >> > -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 05/06/2015 12:21 PM, Jaehoon Chung wrote: > Hi, Zhangfei. > > On 05/06/2015 11:16 AM, zhangfei wrote: >> >> >> On 05/06/2015 09:39 AM, Jaehoon Chung wrote: >>> Hi, >>> >>> On 05/06/2015 10:33 AM, zhangfei wrote: >>>> >>>> >>>> On 05/06/2015 09:26 AM, Jaehoon Chung wrote: >>>>> Hi, >>>>> >>>>> On 05/06/2015 10:14 AM, Zhangfei Gao wrote: >>>>>> On 6 May 2015 at 08:36, Jaehoon Chung <jh80.chung@samsung.com> wrote: >>>>>>> Hi, Zhangfei. >>>>>>> >>>>>>> If you want to check it, use the "broken-cd" and "non-removable" properties into dt-file. >>>>>>> Did you use them? >>>>>> >>>>>> Yes. >>>>>> "broken-cd" can work, but mmc_rescan keeps running. >>>>>> "non-removable" does NOT work, which should be used for emmc. >>>>>> Since dw_mci_get_cd only checks DW_MCI_QUIRK_BROKEN_CARD_DETECTION, so >>>>>> only checks "broken-cd" but not check "non-removable" >>>>> >>>>> Did you use the usage like the below.. >>>>> >>>>> dwmmc0 { >>>>> non-removable; >>>>> broken-cd; >>>>> }; >>>> >>>> non-removable and broken-cd should be used only one. >>> >>> Did you check the code? >>> If non-removable is set, broken-cd should be discarded. >>> >>> I think that the below usage is not "must not". >> >> I understand you meaning, you suggest >>>>> dwmmc0 { >>>>> non-removable; >>>>> broken-cd; >>>>> }; >> >> drivers/mmc/host/dw_mmc.c checks broken-cd, while mmc_of_parse checks non-removable. >> Yes, it works. >> >> But is it a workaround? and a little tricky. >> It costs me some time to find why non-removable does not work, someone else may meet the same issue. >> It does not align with Documentation/devicetree/bindings/mmc/mmc.txt, which is the guideline to write dts. >> And see drivers/mmc/host/sdhci.c: sdhci_do_get_cd, it also checks both. > > "non-removable" is assumed that card is not removed. > it's not also correct detect scheme. Then it's also able to say the broken card detection scheme. > (if CDETECT register can't use.) > > BROKEN_CARD_DETECTION quirk means that it has unreliable card detection. > When dw-mmc host controller has unreliable card detection scheme, it could be set. > Is this tricky? i don't think so. > > Though non-removable doesn't set, it has to work fine, isn't? If non-removable is not set, broken-cd has to be set. Or set both, but usually we may not consider this at first. When we first want to enable emmc, we naturally use non-removable, according to Documentation/devicetree/bindings/mmc/mmc.txt Only one of the properties in this section should be supplied: - broken-cd: There is no card detection available; polling must be used. - cd-gpios: Specify GPIOs for card detection, see gpio binding - non-removable: non-removable slot (like eMMC); assume always present. But unfortunately we find it does not work and took half day to debug, happen to find broken-cd can work, though mmc_rescan is keeps running for a while, and we treat it as workaround. After some time, another person find broken-cd does not make sense, and debug again about non-removable, and took another half day. It really happens here :( So is it better support just using non-removable for emmc, aligning with mmc.txt. > And i don't think that dw-mmc controller must use it since sdhci controller used. > (I have known that sdhci controller is using that.) > > Well, If Ulf thinks this is tricky, i will consider this patch. > Thanks -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 05/06/2015 02:13 PM, Jaehoon Chung wrote: >>>>>>>>> If you want to check it, use the "broken-cd" and "non-removable" properties into dt-file. >>>>>>>>> Did you use them? >>>>>>>> >>>>>>>> Yes. >>>>>>>> "broken-cd" can work, but mmc_rescan keeps running. >>>>>>>> "non-removable" does NOT work, which should be used for emmc. >>>>>>>> Since dw_mci_get_cd only checks DW_MCI_QUIRK_BROKEN_CARD_DETECTION, so >>>>>>>> only checks "broken-cd" but not check "non-removable" >>>>>>> >>>>>>> Did you use the usage like the below.. >>>>>>> >>>>>>> dwmmc0 { >>>>>>> non-removable; >>>>>>> broken-cd; >>>>>>> }; >>>>>> >>>>>> non-removable and broken-cd should be used only one. >>>>> >>>>> Did you check the code? >>>>> If non-removable is set, broken-cd should be discarded. >>>>> >>>>> I think that the below usage is not "must not". >>>> >>>> I understand you meaning, you suggest >>>>>>> dwmmc0 { >>>>>>> non-removable; >>>>>>> broken-cd; >>>>>>> }; >>>> >>>> drivers/mmc/host/dw_mmc.c checks broken-cd, while mmc_of_parse checks non-removable. >>>> Yes, it works. >>>> >>>> But is it a workaround? and a little tricky. >>>> It costs me some time to find why non-removable does not work, someone else may meet the same issue. >>>> It does not align with Documentation/devicetree/bindings/mmc/mmc.txt, which is the guideline to write dts. >>>> And see drivers/mmc/host/sdhci.c: sdhci_do_get_cd, it also checks both. >>> >>> "non-removable" is assumed that card is not removed. >>> it's not also correct detect scheme. Then it's also able to say the broken card detection scheme. >>> (if CDETECT register can't use.) >>> >>> BROKEN_CARD_DETECTION quirk means that it has unreliable card detection. >>> When dw-mmc host controller has unreliable card detection scheme, it could be set. >>> Is this tricky? i don't think so. >>> >>> Though non-removable doesn't set, it has to work fine, isn't? >> If non-removable is not set, broken-cd has to be set. >> Or set both, but usually we may not consider this at first. >> >> When we first want to enable emmc, we naturally use non-removable, according to Documentation/devicetree/bindings/mmc/mmc.txt > > Why do you use naturally non-removable? eMMC can be removed at some SoC. (It's assumption.) > Is it common approach that consider how eMMC can be detected at host controller? The emmc chip we use is folded on board and can not be removed. non-removable will make mmc_rescan only executing once, while broken will make mmc_rescan polling. > >> Only one of the properties in this section should be supplied: >> - broken-cd: There is no card detection available; polling must be used. >> - cd-gpios: Specify GPIOs for card detection, see gpio binding >> - non-removable: non-removable slot (like eMMC); assume always present. >> >> But unfortunately we find it does not work and took half day to debug, happen to find broken-cd can work, though mmc_rescan is keeps running for a while, and we treat it as workaround. >> >> After some time, another person find broken-cd does not make sense, and debug again about non-removable, and took another half day. >> >> It really happens here :( > > Sorry for not saving your time. > Hmm..To prevent your case, it seems better that apply your patch. :) > > Will apply at my dw-mmc tree. Thanks Jaehoon. -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c index 488a8af..5d327e4 100644 --- a/drivers/mmc/host/dw_mmc.c +++ b/drivers/mmc/host/dw_mmc.c @@ -1308,7 +1308,8 @@ static int dw_mci_get_cd(struct mmc_host *mmc) int gpio_cd = mmc_gpio_get_cd(mmc); /* Use platform get_cd function, else try onboard card detect */ - if (brd->quirks & DW_MCI_QUIRK_BROKEN_CARD_DETECTION) + if ((brd->quirks & DW_MCI_QUIRK_BROKEN_CARD_DETECTION) || + (mmc->caps & MMC_CAP_NONREMOVABLE)) present = 1; else if (!IS_ERR_VALUE(gpio_cd)) present = gpio_cd;
When non-removable is used for emmc, MMC_CAP_NONREMOVABLE should also be checked, otherwise detection fail since present=0 Signed-off-by: Zhangfei Gao <zhangfei.gao@linaro.org> --- drivers/mmc/host/dw_mmc.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)