linux-kernel - Re: [PATCH v2 03/11] mmc: mtk-sd: Re-store SDIO IRQs mask at system resume

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Message-ID: <CAPDyKFpaM5Os_B_f=b5aY87Espm6GvGG=C6sRemzvfG=9rE74A@mail.gmail.com>
Date:   Wed, 11 Sep 2019 14:06:35 +0200
From:   Ulf Hansson <ulf.hansson@...aro.org>
To:     Doug Anderson <dianders@...omium.org>
Cc:     Linux MMC List <linux-mmc@...r.kernel.org>,
        Adrian Hunter <adrian.hunter@...el.com>,
        Matthias Kaehlcke <mka@...omium.org>,
        Shawn Lin <shawn.lin@...k-chips.com>,
        Jaehoon Chung <jh80.chung@...sung.com>,
        Yong Mao <yong.mao@...iatek.com>,
        Chaotian Jing <chaotian.jing@...iatek.com>,
        LKML <linux-kernel@...r.kernel.org>,
        Nicolas Boichat <drinkcat@...omium.org>,
        Daniel Kurtz <djkurtz@...omium.org>
Subject: Re: [PATCH v2 03/11] mmc: mtk-sd: Re-store SDIO IRQs mask at system resume

On Tue, 10 Sep 2019 at 00:29, Doug Anderson <dianders@...omium.org> wrote:
>
> Hi,
>
> On Sun, Sep 8, 2019 at 3:12 AM Ulf Hansson <ulf.hansson@...aro.org> wrote:
> >
> > In cases when SDIO IRQs have been enabled, runtime suspend is prevented by
> > the driver. However, this still means msdc_runtime_suspend|resume() gets
> > called during system suspend/resume, via pm_runtime_force_suspend|resume().
> >
> > This means during system suspend/resume, the register context of the mtk-sd
> > device most likely loses its register context, even in cases when SDIO IRQs
> > have been enabled.
> >
> > To re-enable the SDIO IRQs during system resume, the mtk-sd driver
> > currently relies on the mmc core to re-enable the SDIO IRQs when it resumes
> > the SDIO card, but this isn't the recommended solution. Instead, it's
> > better to deal with this locally in the mtk-sd driver, so let's do that.
> >
> > Signed-off-by: Ulf Hansson <ulf.hansson@...aro.org>
> > ---
> >  drivers/mmc/host/mtk-sd.c | 3 +++
> >  1 file changed, 3 insertions(+)
> >
> > diff --git a/drivers/mmc/host/mtk-sd.c b/drivers/mmc/host/mtk-sd.c
> > index 6946bb040a28..ae7688098b7b 100644
> > --- a/drivers/mmc/host/mtk-sd.c
> > +++ b/drivers/mmc/host/mtk-sd.c
> > @@ -2408,6 +2408,9 @@ static void msdc_save_reg(struct msdc_host *host)
> >         } else {
> >                 host->save_para.pad_tune = readl(host->base + tune_reg);
> >         }
> > +
> > +       if (sdio_irq_claimed(host->mmc))
> > +               __msdc_enable_sdio_irq(host, 1);
> >  }
> >
> >  static void msdc_restore_reg(struct msdc_host *host)
>
> I don't personally have a Mediatek device setup to test this patch on.
> If it's super urgent I could try to track down one and try to set it
> up, but hopefully it's easier for someone else...
>
> That being said, from code inspection it seems like you should be
> adding your code to msdc_restore_reg(), not to msdc_save_reg().  Am I
> confused?

No, you are absolutely correct, my bad. Thanks a lot for spotting this!

Kind regards
Uffe