Re: [PATCH] mmc: block: Support Host to control FUA.

[Wenchao Chen]

On Thu, Oct 20, 2022 at 3:44 PM Avri Altman <Avri.Altman@xxxxxxx> wrote:
>
> > According to the above data, disable FUA (fua_disable = 1) improves the
> > performance. Therefore, it is recommended to support the host to control
> > FUA.
> >
> > Signed-off-by: Wenchao Chen <wenchao.chen@xxxxxxxxxx>
> > ---
> >  drivers/mmc/core/block.c | 3 ++-
> >  include/linux/mmc/host.h | 3 +++
> >  2 files changed, 5 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/mmc/core/block.c b/drivers/mmc/core/block.c index
> > 54cd009aee50..333e819e077a 100644
> > --- a/drivers/mmc/core/block.c
> > +++ b/drivers/mmc/core/block.c
> > @@ -2490,7 +2490,8 @@ static struct mmc_blk_data
> > *mmc_blk_alloc_req(struct mmc_card *card,
> >             ((card->ext_csd.rel_param & EXT_CSD_WR_REL_PARAM_EN) ||
> >              card->ext_csd.rel_sectors)) {
> >                 md->flags |= MMC_BLK_REL_WR;
> > -               fua_enabled = true;
> > +               if (!card->host->fua_disable)
> > +                       fua_enabled = true;
> Where are you allowing to set fua_disable?
> And then I would expect you to call blk_queue_flag_set to set QUEUE_FLAG_FUA.
>
> Thanks,
> Avri
Hi Avri
We will implement sdhci_sprd_probe in sdhci-sprd.c host->fua_disable = true;
Because sdhci_sprd_probe is before mmc_blk_alloc_req, calling blk_queue_flag_set
directly will also be updated.

Thanks,
Wenchao
>
> >                 cache_enabled = true;
> >         }
> >         if (mmc_cache_enabled(card->host)) diff --git
> > a/include/linux/mmc/host.h b/include/linux/mmc/host.h index
> > 8fdd3cf971a3..16a5bee3eeae 100644
> > --- a/include/linux/mmc/host.h
> > +++ b/include/linux/mmc/host.h
> > @@ -517,6 +517,9 @@ struct mmc_host {
> >         struct blk_crypto_profile crypto_profile;  #endif
> >
> > +       /* Host FUA support */
> > +       bool                    fua_disable;
> > +
> >         /* Host Software Queue support */
> >         bool                    hsq_enabled;
> >
> > --
> > 2.17.1
>