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

[zhangfei <zhangfei.gao@linaro.org>]

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
>>
>