RE: [PATCH] mmc: add quirk to disable eMMC cache for Micron eMMC v5.0 cards

[Avri Altman <Avri.Altman@wdc.com>]

Scott hi,
Can you take a look at https://lore.kernel.org/lkml/20210322133645.4901-1-avri.altman@wdc.com/
Is there a chance that it will work for you as well?

Thanks,
Avri

> -----Original Message-----
> From: Scott Branden <scott.branden@broadcom.com>
> Sent: Tuesday, 13 April 2021 18:46
> To: Ulf Hansson <ulf.hansson@linaro.org>; Bean Huo (beanhuo)
> <beanhuo@micron.com>; Luca Porzio (lporzio) <lporzio@micron.com>;
> tedirkes@micron.com
> Cc: BCM Kernel Feedback <bcm-kernel-feedback-list@broadcom.com>; linux-
> mmc <linux-mmc@vger.kernel.org>; Linux Kernel Mailing List <linux-
> kernel@vger.kernel.org>; Vladimir Olovyannikov
> <vladimir.olovyannikov@broadcom.com>
> Subject: Re: [PATCH] mmc: add quirk to disable eMMC cache for Micron eMMC
> v5.0 cards
> 
> +Travis Dirkes (with corrected email),
> 
>  Could you provide more details on the Micron data error.
> 
> > On 2021-04-12 12:44 a.m., Ulf Hansson wrote:
> >> + Bean Huo, Luca Porzio
> >>
> >> On Thu, 8 Apr 2021 at 19:59, Scott Branden
> <scott.branden@broadcom.com> wrote:
> >>>
> >>> From: Vladimir Olovyannikov <vladimir.olovyannikov@broadcom.com>
> >>>
> >>> In certain rare combination of operations, Micron eMMC v5.0 cards
> >>> may experience data errors if internal cache is enabled.
> >>> This may lead to eMMC related data errors.
> >>> Introduce a quirk to disable cache on these eMMC cards.
> >>
> >> Can you please elaborate on this, what combinations of operations are
> >> you referring to - and what kind of data errors?
> >>
> >> I have also looped in some of the Micron guys, to let them chim in.
> >>
> >>>
> >>> Signed-off-by: Vladimir Olovyannikov
> <vladimir.olovyannikov@broadcom.com>
> >>> Signed-off-by: Scott Branden <scott.branden@broadcom.com>
> >>
> >> Kind regards
> >> Uffe
> >>
> >>> ---
> >>>  drivers/mmc/core/card.h   | 5 +++++
> >>>  drivers/mmc/core/mmc.c    | 4 ++--
> >>>  drivers/mmc/core/quirks.h | 8 ++++++++
> >>>  include/linux/mmc/card.h  | 1 +
> >>>  4 files changed, 16 insertions(+), 2 deletions(-)
> >>>
> >>> diff --git a/drivers/mmc/core/card.h b/drivers/mmc/core/card.h
> >>> index 7bd392d55cfa..22cea63ac359 100644
> >>> --- a/drivers/mmc/core/card.h
> >>> +++ b/drivers/mmc/core/card.h
> >>> @@ -222,4 +222,9 @@ static inline int mmc_card_broken_hpi(const
> struct mmc_card *c)
> >>>         return c->quirks & MMC_QUIRK_BROKEN_HPI;
> >>>  }
> >>>
> >>> +static inline int mmc_card_broken_cache(const struct mmc_card *c)
> >>> +{
> >>> +       return c->quirks & MMC_QUIRK_BROKEN_CACHE;
> >>> +}
> >>> +
> >>>  #endif
> >>> diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
> >>> index 8741271d3971..cd83b7f0e59c 100644
> >>> --- a/drivers/mmc/core/mmc.c
> >>> +++ b/drivers/mmc/core/mmc.c
> >>> @@ -1820,12 +1820,12 @@ static int mmc_init_card(struct mmc_host
> *host, u32 ocr,
> >>>          * sudden power failure tests. Let's extend the timeout to a minimum of
> >>>          * DEFAULT_CACHE_EN_TIMEOUT_MS and do it for all cards.
> >>>          */
> >>> -       if (card->ext_csd.cache_size > 0) {
> >>> +       if (!mmc_card_broken_cache(card) && card->ext_csd.cache_size > 0)
> {
> >>>                 unsigned int timeout_ms = MIN_CACHE_EN_TIMEOUT_MS;
> >>>
> >>>                 timeout_ms = max(card->ext_csd.generic_cmd6_time,
> timeout_ms);
> >>>                 err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
> >>> -                               EXT_CSD_CACHE_CTRL, 1, timeout_ms);
> >>> +                                EXT_CSD_CACHE_CTRL, 1, timeout_ms);
> >>>                 if (err && err != -EBADMSG)
> >>>                         goto free_card;
> >>>
> >>> diff --git a/drivers/mmc/core/quirks.h b/drivers/mmc/core/quirks.h
> >>> index d68e6e513a4f..23972d87c82a 100644
> >>> --- a/drivers/mmc/core/quirks.h
> >>> +++ b/drivers/mmc/core/quirks.h
> >>> @@ -116,6 +116,14 @@ static const struct mmc_fixup __maybe_unused
> mmc_ext_csd_fixups[] = {
> >>>         MMC_FIXUP_EXT_CSD_REV(CID_NAME_ANY,
> CID_MANFID_NUMONYX,
> >>>                               0x014e, add_quirk, MMC_QUIRK_BROKEN_HPI, 6),
> >>>
> >>> +       /*
> >>> +        * In certain rare combination of operations, Micron eMMC v5.0 cards
> >>> +        * may experience data errors if internal cache is enabled.
> >>> +        * Disabling cache for these cards eliminates the issue.
> >>> +        */
> >>> +       MMC_FIXUP_EXT_CSD_REV(CID_NAME_ANY,
> CID_MANFID_MICRON,
> >>> +                             0x014e, add_quirk, MMC_QUIRK_BROKEN_CACHE, 7),
> >>> +
> >>>         END_FIXUP
> >>>  };
> >>>
> >>> diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h
> >>> index f9ad35dd6012..22f256a4e54e 100644
> >>> --- a/include/linux/mmc/card.h
> >>> +++ b/include/linux/mmc/card.h
> >>> @@ -270,6 +270,7 @@ struct mmc_card {
> >>>  #define MMC_QUIRK_BROKEN_IRQ_POLLING   (1<<11) /* Polling
> SDIO_CCCR_INTx could create a fake interrupt */
> >>>  #define MMC_QUIRK_TRIM_BROKEN  (1<<12)         /* Skip trim */
> >>>  #define MMC_QUIRK_BROKEN_HPI   (1<<13)         /* Disable broken HPI
> support */
> >>> +#define MMC_QUIRK_BROKEN_CACHE (1<<14)         /* Disable broken
> cache */
> >>>
> >>>         bool                    reenable_cmdq;  /* Re-enable Command Queue */
> >>>
> >>> --
> >>> 2.17.1
> >>>
> >