Re: [PATCH] mmc: dw_mmc: dw_mci_get_cd check MMC_CAP_NONREMOVABLE

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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@xxxxxxxxxxx> 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


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