mmc: core: Enable MMC_CAP2_CACHE_CTRL as default

There are no reason to why the use of a non-volatile internal eMMC
cache should be controlled by a host cap. Instead let's just enable it
if the eMMC card supports it.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Seungwon Jeon <tgih.jun@samsung.com>
Signed-off-by: Chris Ball <chris@printf.net>

drivers/mmc/core/core.c

@@ -2562,12 +2562,8 @@ EXPORT_SYMBOL(mmc_power_restore_host);
  */
 int mmc_flush_cache(struct mmc_card *card)
 {
-	struct mmc_host *host = card->host;
 	int err = 0;
 
-	if (!(host->caps2 & MMC_CAP2_CACHE_CTRL))
-		return err;
-
 	if (mmc_card_mmc(card) &&
 			(card->ext_csd.cache_size > 0) &&
 			(card->ext_csd.cache_ctrl & 1)) {

drivers/mmc/core/mmc.c

@@ -1287,8 +1287,7 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr,
 	 * If cache size is higher than 0, this indicates
 	 * the existence of cache and it can be turned on.
 	 */
-	if ((host->caps2 & MMC_CAP2_CACHE_CTRL) &&
-			card->ext_csd.cache_size > 0) {
+	if (card->ext_csd.cache_size > 0) {
 		err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
 				EXT_CSD_CACHE_CTRL, 1,
 				card->ext_csd.generic_cmd6_time);

include/linux/mmc/host.h

@@ -264,7 +264,6 @@ struct mmc_host {
 	u32			caps2;		/* More host capabilities */
 
 #define MMC_CAP2_BOOTPART_NOACC	(1 << 0)	/* Boot partition no access */
-#define MMC_CAP2_CACHE_CTRL	(1 << 1)	/* Allow cache control */
 #define MMC_CAP2_FULL_PWR_CYCLE	(1 << 2)	/* Can do full power cycle */
 #define MMC_CAP2_NO_MULTI_READ	(1 << 3)	/* Multiblock reads don't work */
 #define MMC_CAP2_HS200_1_8V_SDR	(1 << 5)        /* can support */