Hi Arend,
On Mon, Nov 11, 2013 at 5:49 PM, Arend van Spriel <arend@xxxxxxxxxxxx> wrote:
> When the host->tuning_count is zero it means that the
> retuning is disabled. This is checked on the first
> run of sdhci_execute_tuning() by the if statement below:
>
> if (!(host->flags & SDHCI_NEEDS_RETUNING) && host->tuning_count &&
> (host->tuning_mode == SDHCI_TUNING_MODE_1)) {
>
> So only when tuning_count is non-zero it will set the host
> flag SDHCI_USING_RETUNING_TIMER. The else statement is only
> for re-programming the timer, which means that flag must be
> set. Because that is not checked the else statement is executed
> in the first run when tuning_count is zero.
>
> This was seen on a host controller which indicated
> SDHCI_TUNING_MODE_1 (0) and tuning_count being zero. Suspect
> that (one of) these registers is not properly set.
>
> Signed-off-by: Arend van Spriel <arend@xxxxxxxxxxxx>
> ---
> This patch applies to the mmc-next branch.
>
> V2:
> - add more explanation to the commit message
> - check host flag SDHCI_USING_RETUNING_TIMER
> ---
> drivers/mmc/host/sdhci.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> index bd8a098..5974599 100644
> --- a/drivers/mmc/host/sdhci.c
> +++ b/drivers/mmc/host/sdhci.c
> @@ -2014,7 +2014,7 @@ out:
> host->tuning_count * HZ);
> /* Tuning mode 1 limits the maximum data length to 4MB */
> mmc->max_blk_count = (4 * 1024 * 1024) / mmc->max_blk_size;
> - } else {
> + } else if (host->flags & SDHCI_USING_RETUNING_TIMER) {
> host->flags &= ~SDHCI_NEEDS_RETUNING;
> /* Reload the new initial value for timer */
> if (host->tuning_mode == SDHCI_TUNING_MODE_1)
I wonder if we could also remove this line?
It looks to me it's not neccesary to check the tuning_mode again since
we already check the flag
above and SDHCI_TUNING_MODE_1 seems like the prerequisite of
SDHCI_USING_RETUNING_TIMER.
Regards
Dong Aisheng
> --
> 1.7.10.4
>
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-mmc" in
> the body of a message to majordomo@xxxxxxxxxxxxxxx
> More majordomo info at http://vger.kernel.org/majordomo-info.html
--
To unsubscribe from this list: send the line "unsubscribe linux-mmc" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
