Re: [PATCH v2] mmc: sdhci-of-arasan: fix set_clock when a phy is supported

[Shawn Lin]

å 2016/4/28 18:38, Ulf Hansson åé:
> On 28 April 2016 at 10:38, Shawn Lin <shawn.lin@xxxxxxxxxxxxxx> wrote:
> > commit 61b914eb81f8 ("mmc: sdhci-of-arasan: add phy support for
> > sdhci-of-arasan") introduce phy support for arasan. According to
> > the vendor's databook, we should make sure the phy is in poweroff
> > status before we configure the clk stuff. Otherwise it may cause
> > some IO sample timing issues from the test. And we don't need this
> > extra operation while running in low performance mode since phy
> > doesn't trigger sampling block.
> >
> > Signed-off-by: Shawn Lin <shawn.lin@xxxxxxxxxxxxxx>
>
> Thanks, applied for next!

Thanks for applying v2 but, could you please drop it and applied v3
I just send :) .
Because v2 introduces a bug. Set_clock callback will be
called under the protection of spinlock in sdhci_do_set_ios. However
PHY APIs need mutex which fails the kernel's debug check

BUG: sleeping function called from invalid context at kernel/locking/mutex.c

> Kind regards
> Uffe
>
> > ---
> >
> > Changes in v2:
> > - change commit msg title to indicate it's a fix
> > - fix a typo in commmit msg
> >
> >  drivers/mmc/host/sdhci-of-arasan.c | 20 +++++++++++++++++++-
> >  1 file changed, 19 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/mmc/host/sdhci-of-arasan.c b/drivers/mmc/host/sdhci-of-arasan.c
> > index 2e482b1..20b859e 100644
> > --- a/drivers/mmc/host/sdhci-of-arasan.c
> > +++ b/drivers/mmc/host/sdhci-of-arasan.c
> > @@ -55,8 +55,26 @@ static unsigned int sdhci_arasan_get_timeout_clock(struct sdhci_host *host)
> >         return freq;
> >  }
> >
> > +static void sdhci_arasan_set_clock(struct sdhci_host *host, unsigned int clock)
> > +{
> > +       struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
> > +       struct sdhci_arasan_data *sdhci_arasan = sdhci_pltfm_priv(pltfm_host);
> > +       bool ctrl_phy = false;
> > +
> > +       if (clock > MMC_HIGH_52_MAX_DTR && (!IS_ERR(sdhci_arasan->phy)))
> > +               ctrl_phy = true;
> > +
> > +       if (ctrl_phy)
> > +               phy_power_off(sdhci_arasan->phy);
> > +
> > +       sdhci_set_clock(host, clock);
> > +
> > +       if (ctrl_phy)
> > +               phy_power_on(sdhci_arasan->phy);
> > +}
> > +
> >  static struct sdhci_ops sdhci_arasan_ops = {
> > -       .set_clock = sdhci_set_clock,
> > +       .set_clock = sdhci_arasan_set_clock,
> >         .get_max_clock = sdhci_pltfm_clk_get_max_clock,
> >         .get_timeout_clock = sdhci_arasan_get_timeout_clock,
> >         .set_bus_width = sdhci_set_bus_width,
> > --
> > 2.3.7
> >
> >
> > --
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--
Best Regards
Shawn Lin