+ Bean Huo, Luca Porzio
On Thu, 8 Apr 2021 at 19:59, Scott Branden <scott.branden@xxxxxxxxxxxx> wrote:
>
> From: Vladimir Olovyannikov <vladimir.olovyannikov@xxxxxxxxxxxx>
>
> 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@xxxxxxxxxxxx>
> Signed-off-by: Scott Branden <scott.branden@xxxxxxxxxxxx>
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
>
