Re: [PATCH] mmc: dw_mmc: update clock after ctrl reset in runtime resume

[Ziyuan <xzy.xu-TNX95d0MmH7DzftRWevZcw@public.gmane.org>]

On 01/04/2017 04:28 PM, Jaehoon Chung wrote:
> On 01/03/2017 03:59 PM, Shawn Lin wrote:
>> Hi Ziyuan,
>>
>> On 2017/1/3 14:46, Ziyuan Xu wrote:
>>> Immediately after reset, issue the command which sets
>>> update_clock_register_only bit, the card clock will restart.
>>>
>>> MMC_PM_KEEP_POWER is disabled for SD card and eMMC slots, so that they
>>> have no chance to invoke dw_mci_setup_bus for update clock behaviour.
>>> Let's consummate it.
>>>
>>> Fixes: e9ed883 ("mmc: dw_mmc: add runtime PM callback")
>>> Reported-by: Randy Li <randy.li-TNX95d0MmH7DzftRWevZcw@public.gmane.org>
>>> Signed-off-by: Ziyuan Xu <xzy.xu-TNX95d0MmH7DzftRWevZcw@public.gmane.org>
>>> ---
>>>   drivers/mmc/host/dw_mmc.c | 2 ++
>>>   1 file changed, 2 insertions(+)
>>>
>>> diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
>>> index b44306b..71715b4 100644
>>> --- a/drivers/mmc/host/dw_mmc.c
>>> +++ b/drivers/mmc/host/dw_mmc.c
>>> @@ -3357,6 +3357,8 @@ int dw_mci_runtime_resume(struct device *dev)
>>>           if (slot->mmc->pm_flags & MMC_PM_KEEP_POWER) {
>>>               dw_mci_set_ios(slot->mmc, &slot->mmc->ios);
>>>               dw_mci_setup_bus(slot, true);
>>> +        } else {
>>> +            mci_send_cmd(slot, SDMMC_CMD_UPD_CLK, 0);
>>>           }
>>>       }
>> Thanks for sending this, but I think the better fix we talked about
>> offlist may be...
>>
>> --- a/drivers/mmc/host/dw_mmc.c
>> +++ b/drivers/mmc/host/dw_mmc.c
>> @@ -3324,7 +3324,7 @@ int dw_mci_runtime_resume(struct device *dev)
>>          if (ret)
>>                  goto err;
>>
>> -       if (!dw_mci_ctrl_reset(host, SDMMC_CTRL_ALL_RESET_FLAGS)) {
>> +       if (!dw_mci_reset(host)) {
>>                  clk_disable_unprepare(host->ciu_clk);
>>                  ret = -ENODEV;
>>                  goto err;
>>
>>
>> otherwise there still some unhandled cases once the reset is failure.
> I  think Shawn's suggestion is more better..After applied Shawn's suggestion, Is the problem  disappeared?
> If then, could you resend the patch as Shawn's?
> I  don't test yet with exynos..after testing, i will also share.

Fine. It a better approach. I will test it and share result ASAP.:-)

BR
Ziyuan Xu

>
> Best Regards,
> Jaehoon Chung
>
>>>
>>
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