Re: [PATCH v2] mmc: mmci: manage MMC_CAP_NEED_RSP_BUSY for stm32 variant

[Yann Gautier <yann.gautier@foss.st.com>]

On 3/2/21 11:40 AM, Ulf Hansson wrote:
> On Thu, 25 Feb 2021 at 15:55, Yann Gautier <yann.gautier@foss.st.com> wrote:
>>
>> To properly manage commands awaiting R1B responses, the capability
>> MMC_CAP_NEED_RSP_BUSY is enabled in mmci driver, for stm32 variant.
>> The issue was seen on STM32MP157C-EV1 board, with an erase command,
>> with secure erase argument, letting the card stuck, possibly waiting
>> for 4 hours before timeout.
>>
>> Fixes: 94fe2580a2f3 ("mmc: core: Enable erase/discard/trim support for all mmc hosts")
>>
>> Signed-off-by: Yann Gautier <yann.gautier@foss.st.com>
>> ---
>> This is somehow a v2 for patch [1].
>> Changes:
>> - Only apply MMC_CAP_NEED_RSP_BUSY to stm32 variant
>> - Cap the used timeout written to MMCIDATATIMER (when using
>> MMC_CAP_NEED_RSP_BUSY, cmd->busy_timeout may be greater than
>> host->max_busy_timeout)
>>
>>   [1] https://patchwork.kernel.org/project/linux-mmc/patch/20210204120547.15381-2-yann.gautier@foss.st.com/
>>
>>   drivers/mmc/host/mmci.c             | 8 +++++++-
>>   drivers/mmc/host/mmci_stm32_sdmmc.c | 1 +
>>   2 files changed, 8 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
>> index 17dbc81c221e..89e0e9ccfb71 100644
>> --- a/drivers/mmc/host/mmci.c
>> +++ b/drivers/mmc/host/mmci.c
>> @@ -1242,7 +1242,13 @@ mmci_start_command(struct mmci_host *host, struct mmc_command *cmd, u32 c)
>>                  if (!cmd->busy_timeout)
>>                          cmd->busy_timeout = 10 * MSEC_PER_SEC;
>>
>> -               clks = (unsigned long long)cmd->busy_timeout * host->cclk;
>> +               if (host->mmc->caps & MMC_CAP_NEED_RSP_BUSY &&
>> +                   host->mmc->max_busy_timeout &&
>> +                   cmd->busy_timeout > host->mmc->max_busy_timeout)
> 
> We are already within "if (host->variant->busy_timeout ....", a few
> lines above, which means this can be simplified into:
> 
> if (cmd->busy_timeout > host->mmc->max_busy_timeout)
> 
>> +                       clks = (unsigned long long)host->mmc->max_busy_timeout * host->cclk;
>> +               else
>> +                       clks = (unsigned long long)cmd->busy_timeout * host->cclk;
>> +
>>                  do_div(clks, MSEC_PER_SEC);
>>                  writel_relaxed(clks, host->base + MMCIDATATIMER);
>>          }
>> diff --git a/drivers/mmc/host/mmci_stm32_sdmmc.c b/drivers/mmc/host/mmci_stm32_sdmmc.c
>> index 51db30acf4dc..2ad577618324 100644
>> --- a/drivers/mmc/host/mmci_stm32_sdmmc.c
>> +++ b/drivers/mmc/host/mmci_stm32_sdmmc.c
>> @@ -522,6 +522,7 @@ void sdmmc_variant_init(struct mmci_host *host)
>>
>>          host->ops = &sdmmc_variant_ops;
>>          host->pwr_reg = readl_relaxed(host->base + MMCIPOWER);
>> +       host->mmc->caps |= MMC_CAP_NEED_RSP_BUSY;
> 
> To make it more clear that this is for variants having the
> ->busy_timeout flag set, I suggest to move this into mmci_probe().
> 
>>
>>          base_dlyb = devm_of_iomap(mmc_dev(host->mmc), np, 1, NULL);
>>          if (IS_ERR(base_dlyb))
>> --
>> 2.17.1
>>
> 
> Well, I decided to help out a bit. I have amend the patch according to
> the above and extended the commit message with some valuable
> information, based upon our earlier discussions.
> 
> Patch is applied at my fixes branch with a stable tag, please have a
> look, test and shout at me if there is something that looks wrong!
> 
> Thanks and kind regards
> Uffe
> 

Hi Ulf,

Thanks a lot for the updated patch.
I've tested it on STM32MP157C-EV1. The MMC_TEST full campaigns for both 
SD-card and eMMC run OK.


Best regards,
Yann