On 4/12/23 17:01, Jorge Ramirez-Ortiz wrote:
> Requesting a retune before switching to the RPMB partition has been
> observed to cause CRC errors on the RPMB reads (-EILSEQ).
There are still 2 concerns:
1) We don't really know the root cause. Have you determined
if here are CRC errors in the main partition also?
2) Forcing this on everyone
The original idea was that because re-tuning cannot be
done in RPMB, the need to re-rune in RPMB could be avoided
by always re-tuning before switching to RPMB and then switching
straight back. IIRC re-tuning should guarantee at least 4MB
more I/O without issue.
The alternative to dropping re-tuning in this case could
be to add a retry loop for MMC_DRV_OP_IOCTL_RPMB if the error
is -EILSEQ
>
> Since RPMB reads can not be retried, the clients would be directly
> affected by the errors.
>
> This commit disables the request prior to RPMB switching while allowing
> the pause interface to still request a retune before the pause for other
> use cases.
>
> This was verified with the sdhci-of-arasan driver (ZynqMP) configured
> for HS200 using two separate eMMC cards (DG4064 and 064GB2). In both
> cases, the error was easy to reproduce triggering every few tenths of
> reads.
>
> Signed-off-by: Jorge Ramirez-Ortiz <jorge@xxxxxxxxxxxx>
> ---
> drivers/mmc/core/block.c | 2 +-
> drivers/mmc/core/host.c | 7 ++++---
> drivers/mmc/core/host.h | 2 +-
> 3 files changed, 6 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/mmc/core/block.c b/drivers/mmc/core/block.c
> index f9a5cffa64b1..1d69078ad9b2 100644
> --- a/drivers/mmc/core/block.c
> +++ b/drivers/mmc/core/block.c
> @@ -859,7 +859,7 @@ static int mmc_blk_part_switch_pre(struct mmc_card *card,
> if (ret)
> return ret;
> }
> - mmc_retune_pause(card->host);
> + mmc_retune_pause(card->host, false);
> }
>
> return ret;
> diff --git a/drivers/mmc/core/host.c b/drivers/mmc/core/host.c
> index 096093f7be00..a9b95aaa2235 100644
> --- a/drivers/mmc/core/host.c
> +++ b/drivers/mmc/core/host.c
> @@ -119,13 +119,14 @@ void mmc_retune_enable(struct mmc_host *host)
>
> /*
> * Pause re-tuning for a small set of operations. The pause begins after the
> - * next command and after first doing re-tuning.
> + * next command and, if retune is set, after first doing re-tuning.
> */
> -void mmc_retune_pause(struct mmc_host *host)
> +void mmc_retune_pause(struct mmc_host *host, bool retune)
> {
> if (!host->retune_paused) {
> host->retune_paused = 1;
> - mmc_retune_needed(host);
> + if (retune)
> + mmc_retune_needed(host);
Better to just drop mmc_retune_needed(host);
> mmc_retune_hold(host);
There is still a small chance that re-tuning
is needed anyway in which case it will still be done.
> }
> }
> diff --git a/drivers/mmc/core/host.h b/drivers/mmc/core/host.h
> index 48c4952512a5..321776b52270 100644
> --- a/drivers/mmc/core/host.h
> +++ b/drivers/mmc/core/host.h
> @@ -18,7 +18,7 @@ void mmc_retune_disable(struct mmc_host *host);
> void mmc_retune_hold(struct mmc_host *host);
> void mmc_retune_release(struct mmc_host *host);
> int mmc_retune(struct mmc_host *host);
> -void mmc_retune_pause(struct mmc_host *host);
> +void mmc_retune_pause(struct mmc_host *host, bool retune);
> void mmc_retune_unpause(struct mmc_host *host);
>
> static inline void mmc_retune_clear(struct mmc_host *host)
