mmc: core: Separate the timeout value for cache-ctrl

Turning the cache off implies flushing cache which doesn't define
maximum timeout unlike cache-on. This patch will apply the generic
CMD6 timeout only for cache-on. Additionally the kernel message is
added for checking failure case of cache-on.

Signed-off-by: Seungwon Jeon <tgih.jun@samsung.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index f0a9f1f..67f346e 100644
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -1077,14 +1077,23 @@
 	if ((host->caps2 & MMC_CAP2_CACHE_CTRL) &&
 			card->ext_csd.cache_size > 0) {
 		err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
-				EXT_CSD_CACHE_CTRL, 1, 0);
+				EXT_CSD_CACHE_CTRL, 1,
+				card->ext_csd.generic_cmd6_time);
 		if (err && err != -EBADMSG)
 			goto free_card;
 
 		/*
 		 * Only if no error, cache is turned on successfully.
 		 */
-		card->ext_csd.cache_ctrl = err ? 0 : 1;
+		if (err) {
+			pr_warning("%s: Cache is supported, "
+					"but failed to turn on (%d)\n",
+					mmc_hostname(card->host), err);
+			card->ext_csd.cache_ctrl = 0;
+			err = 0;
+		} else {
+			card->ext_csd.cache_ctrl = 1;
+		}
 	}
 
 	if (!oldcard)