On 20/12/22 01:41, Shyam Saini wrote:
> As per the JEDEC spec, tuning(command CMD21) is not allowed in
> RPMB partition.
>
> To avoid retuning while switching to RPMB, hold_retune variable was
> introduced
No, mmc_retune_pause() is used:
/*
* Pause re-tuning for a small set of operations. The pause begins after the
* next command and after first doing re-tuning.
*/
void mmc_retune_pause(struct mmc_host *host)
{
if (!host->retune_paused) {
host->retune_paused = 1;
mmc_retune_needed(host);
mmc_retune_hold(host);
}
}
> but it is not taken into account while making the tuning
> decision. As a consequence of this, mmc driver aborts while switching to
> RPMB partition:
> mmc0: mmc_hs400_to_hs200 failed, error -84
Do you normally re-tune at all? It could just be that re-tuning
doesn't work.
>
> To fix this, take hold_retune variable into account while making retune
> decision in mmc_retune() function.
>
> Fixes: 57da0c042f4a ("mmc: block: Pause re-tuning while switched to the RPMB partition")
> Reported-by: Judy Wang <wangjudy@xxxxxxxxxxxxxxxxxxx>
> Signed-off-by: Shyam Saini <shyamsaini@xxxxxxxxxxxxxxxxxxx>
> ---
> drivers/mmc/core/host.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/drivers/mmc/core/host.c b/drivers/mmc/core/host.c
> index b89dca1f15e9..342c1f5c256b 100644
> --- a/drivers/mmc/core/host.c
> +++ b/drivers/mmc/core/host.c
> @@ -181,6 +181,9 @@ int mmc_retune(struct mmc_host *host)
> bool return_to_hs400 = false;
> int err;
>
> + if (host->hold_retune >= 1)
> + return 0;
No, hold_retune is set *before* the command *after* which
tuning is not permitted.
> +
> if (host->retune_now)
> host->retune_now = 0;
> else
> --
> 2.34.1
>
On 20/12/22 01:41, Shyam Saini wrote:
> Hi All,
>
> Cc'ing Tyler
>
> Please note that I am not 100 % sure about the fix.
> This issue is reproducible without this patch and the patch at least fix the issue without
> any regressions on our side.
>
> We observed that hold_retune is always greater or equal to 1 in mmc_retune() function,
>
> so it may always avoid re-tuning when it is actually needed and there may
>
> be a better fix for the issue.
>
> Please let me know your any feedback or comments.
>
> Best Regards,
> Shyam
>
>
