On 6 March 2014 10:29, Arend van Spriel <arend@xxxxxxxxxxxx> wrote:
> On 02/21/2014 08:59 PM, Arend van Spriel 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.
>>
>> Cc: Dong Aisheng <dongas86@xxxxxxxxx>
>> Cc: Aaron Lu <aaron.lwe@xxxxxxxxx>
>> Signed-off-by: Arend van Spriel <arend@xxxxxxxxxxxx>
>> ---
>> Noticed this patch was still not applied so please reconsider
>> taking it in and let me know. The patch has been rebased and
>> applies to the mmc-next branch.
>
> ping? Am I on some spam filter? What is needed to get this change applied?
>
> Regards,
> Arend
>
>> Regards,
>> Arend
>>
>> V3:
>> - remote tuning mode check for retuning timer reload
>>
>> V2:
>> - add more explanation to the commit message
>> - check host flag SDHCI_USING_RETUNING_TIMER
>> ---
>> drivers/mmc/host/sdhci.c | 7 +++----
>> 1 file changed, 3 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
>> index 9ddef47..d5b421d 100644
>> --- a/drivers/mmc/host/sdhci.c
>> +++ b/drivers/mmc/host/sdhci.c
>> @@ -2026,12 +2026,11 @@ 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)
>> - mod_timer(&host->tuning_timer, jiffies +
>> - host->tuning_count * HZ);
>> + mod_timer(&host->tuning_timer, jiffies +
>> + host->tuning_count * HZ);
>> }
>>
>> /*
>>
>
I don't have any deeper insight about the retuning mechanism for
sdhci, still this seems reasonable.
Acked-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
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