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) -- 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