Re: [PATCH v2 1/2] sdhci: tegra: Implement Tegra specific set_timeout callback

[Ulf Hansson]

On Wed, 15 Apr 2020 at 19:55, Naresh Kamboju <naresh.kamboju@xxxxxxxxxx> wrote:
>
> On Fri, 13 Mar 2020 at 06:41, Sowjanya Komatineni
> <skomatineni@xxxxxxxxxx> wrote:
> >
> > Tegra host supports HW busy detection and timeouts based on the
> > count programmed in SDHCI_TIMEOUT_CONTROL register and max busy
> > timeout it supports is 11s in finite busy wait mode.
> >
> > Some operations like SLEEP_AWAKE, ERASE and flush cache through
> > SWITCH commands take longer than 11s and Tegra host supports
> > infinite HW busy wait mode where HW waits forever till the card
> > is busy without HW timeout.
> >
> > This patch implements Tegra specific set_timeout sdhci_ops to allow
> > switching between finite and infinite HW busy detection wait modes
> > based on the device command expected operation time.
> >
> > Signed-off-by: Sowjanya Komatineni <skomatineni@xxxxxxxxxx>
> > ---
> >  drivers/mmc/host/sdhci-tegra.c | 31 +++++++++++++++++++++++++++++++
> >  1 file changed, 31 insertions(+)
> >
> > diff --git a/drivers/mmc/host/sdhci-tegra.c b/drivers/mmc/host/sdhci-tegra.c
> > index a25c3a4..fa8f6a4 100644
> > --- a/drivers/mmc/host/sdhci-tegra.c
> > +++ b/drivers/mmc/host/sdhci-tegra.c
> > @@ -45,6 +45,7 @@
> >  #define SDHCI_TEGRA_CAP_OVERRIDES_DQS_TRIM_SHIFT       8
> >
> >  #define SDHCI_TEGRA_VENDOR_MISC_CTRL                   0x120
> > +#define SDHCI_MISC_CTRL_ERASE_TIMEOUT_LIMIT            BIT(0)
> >  #define SDHCI_MISC_CTRL_ENABLE_SDR104                  0x8
>
> >  #define SDHCI_MISC_CTRL_ENABLE_SDR50                   0x10
> >  #define SDHCI_MISC_CTRL_ENABLE_SDHCI_SPEC_300          0x20
> > @@ -1227,6 +1228,34 @@ static u32 sdhci_tegra_cqhci_irq(struct sdhci_host *host, u32 intmask)
> >         return 0;
> >  }
> >
> > +static void tegra_sdhci_set_timeout(struct sdhci_host *host,
> > +                                   struct mmc_command *cmd)
> > +{
> > +       u32 val;
> > +
> > +       /*
> > +        * HW busy detection timeout is based on programmed data timeout
> > +        * counter and maximum supported timeout is 11s which may not be
> > +        * enough for long operations like cache flush, sleep awake, erase.
> > +        *
> > +        * ERASE_TIMEOUT_LIMIT bit of VENDOR_MISC_CTRL register allows
> > +        * host controller to wait for busy state until the card is busy
> > +        * without HW timeout.
> > +        *
> > +        * So, use infinite busy wait mode for operations that may take
> > +        * more than maximum HW busy timeout of 11s otherwise use finite
> > +        * busy wait mode.
> > +        */
> > +       val = sdhci_readl(host, SDHCI_TEGRA_VENDOR_MISC_CTRL);
> > +       if (cmd && cmd->busy_timeout >= 11 * HZ)
> > +               val |= SDHCI_MISC_CTRL_ERASE_TIMEOUT_LIMIT;
> > +       else
> > +               val &= ~SDHCI_MISC_CTRL_ERASE_TIMEOUT_LIMIT;
> > +       sdhci_writel(host, val, SDHCI_TEGRA_VENDOR_MISC_CTRL);
> > +
> > +       __sdhci_set_timeout(host, cmd);
>
> kernel build on arm and arm64 architecture failed on stable-rc 4.19
> (arm), 5.4 (arm64) and 5.5 (arm64)
>
> drivers/mmc/host/sdhci-tegra.c: In function 'tegra_sdhci_set_timeout':
> drivers/mmc/host/sdhci-tegra.c:1256:2: error: implicit declaration of
> function '__sdhci_set_timeout'; did you mean
> 'tegra_sdhci_set_timeout'? [-Werror=implicit-function-declaration]
>   __sdhci_set_timeout(host, cmd);
>   ^~~~~~~~~~~~~~~~~~~
>   tegra_sdhci_set_timeout
>
> Full build log,
> https://ci.linaro.org/view/lkft/job/openembedded-lkft-linux-stable-rc-5.5/DISTRO=lkft,MACHINE=am57xx-evm,label=docker-lkft/83/consoleText
> https://ci.linaro.org/view/lkft/job/openembedded-lkft-linux-stable-rc-5.4/DISTRO=lkft,MACHINE=juno,label=docker-lkft/158/consoleText
> https://ci.linaro.org/view/lkft/job/openembedded-lkft-linux-stable-rc-4.19/DISTRO=lkft,MACHINE=am57xx-evm,label=docker-lkft/511/consoleText
>
> - Naresh

Thanks for reporting! What a mess.

It turns out that the commit that was queued for stable that is
causing the above errors, also requires another commit.

The commit that was queued:
5e958e4aacf4 ("sdhci: tegra: Implement Tegra specific set_timeout callback")

The additional commit needed (which was added in v5.6-rc1):
7d76ed77cfbd ("mmc: sdhci: Refactor sdhci_set_timeout()")

However, the above commit needs a manual backport (quite trivial, but
still) for the relevant stable kernels, to allow it to solve the build
problems.

Greg, Sasha - I suggest you to drop the offending commit from the
stable kernels, for now. I think it's better to let Sowjanya deal with
the backports, then send them in small series instead.

Kind regards
Uffe