Re: [PATCH] mmc: core: disable the cache before suspend only afterstopping BKOPS

[Subhash Jadavani]

As Maya is going to fix the commit text,
Acked-by: Subhash Jadavani <subhashj@xxxxxxxxxxxxxx>

On 1/17/2013 12:18 PM, Seungwon Jeon wrote:
> On Thursday, January 17, 2013 , Ulf Hansson wrote:
> > On 13 January 2013 22:47, Maya Erez <merez@xxxxxxxxxxxxxx> wrote:
> > > -----Original Message-----
> > > From: Subhash Jadavani [mailto:subhashj@xxxxxxxxxxxxxx]
> > > Sent: Saturday, January 12, 2013 9:07 AM
> > > To: Maya Erez
> > > Cc: linux-mmc@xxxxxxxxxxxxxxx; linux-arm-msm@xxxxxxxxxxxxxxx; open list
> > > Subject: Re: [PATCH] mmc: core: disable the cache before suspend only after
> > > stopping BKOPS
> > >
> > > On 1/12/2013 2:12 AM, Maya Erez wrote:
> > > > mmc_cache_ctrl was called in runtime suspend before MMC interrupted
> > > > BKOPS in case it is still running on the card. This caused the cache
> > > > disable to timeout.
> > > I guess even if the idle time bkops polling is not implemented, this patch
> > > is good to have. cache control is the eMMC feature and in that sense, it
> > > should have been part of MMC's bus resume (mmc_resume) rather than generic
> > > mmc_suspend_host().
> > >
> > > Patch as such is fine and if you agree, you may want to remove the
> > > mentioning of bkops as part of commit text and may just want to mention
> > > above reason as the main motivation for this patch.
> > >
> > > Agreed, I will change the commit text in the next uploaded version.
> > >
> > > > Therefore, mmc_cache_ctrl has to move to mmc_suspend where we are sure
> > > > that the card can go into suspend and there is no pending activity.
> > > >
> > > > Signed-off-by: Maya Erez <merez@xxxxxxxxxxxxxx>
> > > > ---
> > > >    drivers/mmc/core/core.c |    7 +------
> > > >    drivers/mmc/core/mmc.c  |    8 +++++++-
> > > >    2 files changed, 8 insertions(+), 7 deletions(-)
> > > >
> > > > diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c index
> > > > aaed768..b438bb2 100644
> > > > --- a/drivers/mmc/core/core.c
> > > > +++ b/drivers/mmc/core/core.c
> > > > @@ -2388,6 +2388,7 @@ EXPORT_SYMBOL(mmc_flush_cache);
> > > >     * Turn the cache ON/OFF.
> > > >     * Turning the cache OFF shall trigger flushing of the data
> > > >     * to the non-volatile storage.
> > > > + * This function should be called with host claimed
> > > >     */
> > > >    int mmc_cache_ctrl(struct mmc_host *host, u8 enable)
> > > >    {
> > > > @@ -2399,7 +2400,6 @@ int mmc_cache_ctrl(struct mmc_host *host, u8 enable)
> > > >                        mmc_card_is_removable(host))
> > > >                return err;
> > > >
> > > > -     mmc_claim_host(host);
> > > >        if (card && mmc_card_mmc(card) &&
> > > >                        (card->ext_csd.cache_size > 0)) {
> > > >                enable = !!enable;
> > > > @@ -2417,7 +2417,6 @@ int mmc_cache_ctrl(struct mmc_host *host, u8 enable)
> > > >                                card->ext_csd.cache_ctrl = enable;
> > > >                }
> > > >        }
> > > > -     mmc_release_host(host);
> > > >
> > > >        return err;
> > > >    }
> > > > @@ -2436,10 +2435,6 @@ int mmc_suspend_host(struct mmc_host *host)
> > > >        cancel_delayed_work(&host->detect);
> > > >        mmc_flush_scheduled_work();
> > > >
> > > > -     err = mmc_cache_ctrl(host, 0);
> > > > -     if (err)
> > > > -             goto out;
> > > > -
> > > >        mmc_bus_get(host);
> > > >        if (host->bus_ops && !host->bus_dead) {
> > > >                if (host->bus_ops->suspend) {
> > > > diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c index
> > > > e6e3911..dc17d40 100644
> > > > --- a/drivers/mmc/core/mmc.c
> > > > +++ b/drivers/mmc/core/mmc.c
> > > > @@ -1379,6 +1379,11 @@ static int mmc_suspend(struct mmc_host *host)
> > > >        BUG_ON(!host->card);
> > > >
> > > >        mmc_claim_host(host);
> > > > +
> > > > +     err = mmc_cache_ctrl(host, 0);
> > > > +     if (err)
> > > > +             goto out;
> > > > +
> > > >        if (mmc_can_poweroff_notify(host->card))
> > > >                err = mmc_poweroff_notify(host->card,
> > > EXT_CSD_POWER_OFF_SHORT);
> > > >        else if (mmc_card_can_sleep(host))
> > > > @@ -1386,8 +1391,9 @@ static int mmc_suspend(struct mmc_host *host)
> > > >        else if (!mmc_host_is_spi(host))
> > > >                err = mmc_deselect_cards(host);
> > > >        host->card->state &= ~(MMC_STATE_HIGHSPEED |
> > > MMC_STATE_HIGHSPEED_200);
> > > > -     mmc_release_host(host);
> > > >
> > > > +out:
> > > > +     mmc_release_host(host);
> > > >        return err;
> > > >    }
> > > --
> > > QUALCOMM ISRAEL, on behalf of Qualcomm Innovation Center, Inc. is a member
> > > of Code Aurora Forum, hosted by The Linux Foundation
> > >
> > > --
> > > To unsubscribe from this list: send the line "unsubscribe linux-mmc" in
> > > the body of a message to majordomo@xxxxxxxxxxxxxxx
> > > More majordomo info at  http://vger.kernel.org/majordomo-info.html
> > I agree that some update to the commit msg is wanted; since this fixup
> > is not related to runtime suspend as such.
> > Anyway, you have my ack!
> >
> > Acked-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
> Yes, it's reasonable.
> Cache feature is closely connected with eMMC.
>
> Acked-by: Seungwon Jeon <tgin.jun@xxxxxxxxxxx>
>
> Thanks,
> Seungwon Jeon
> > Kind regards
> > Ulf Hansson
> > --
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