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

[Yann Gautier]

On 3/2/21 11:40 AM, Ulf Hansson wrote:
> On Thu, 25 Feb 2021 at 15:55, Yann Gautier <yann.gautier@xxxxxxxxxxx> 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@xxxxxxxxxxx>
> > ---
> > 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@xxxxxxxxxxx/
> >
> >   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