mmc: mmc: Attempt to flush cache before reset

CMD0 or hardware reset may invalidate the cache, so it needs to be
flushed before reset.

In the case of recovery, we can't expect flushing the cache to work
always, but have a go and ignore errors.
Signed-off-by: NAdrian Hunter <adrian.hunter@intel.com>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

drivers/mmc/core/mmc.c

@@ -1958,6 +1958,12 @@ static int mmc_reset(struct mmc_host *host)
 {
 	struct mmc_card *card = host->card;
 
+	/*
+	 * In the case of recovery, we can't expect flushing the cache to work
+	 * always, but we have a go and ignore errors.
+	 */
+	mmc_flush_cache(host->card);
+
 	if ((host->caps & MMC_CAP_HW_RESET) && host->ops->hw_reset &&
 	     mmc_can_reset(card)) {
 		/* If the card accept RST_n signal, send it. */