mmc: core: Add cache control for eMMC4.5 device

This patch adds cache feature of eMMC4.5 Spec.
If device supports cache capability, host can utilize some specific
operations.

Signed-off-by: Seungwon Jeon <tgih.jun@samsung.com>
Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Chris Ball <cjb@laptop.org>

1 files changed, 8 insertions, 6 deletions

diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
index 370472797ff..c0cb225bbb4 100644
--- a/drivers/mmc/card/block.c
+++ b/drivers/mmc/card/block.c
@@ -851,16 +851,18 @@ out:
 static int mmc_blk_issue_flush(struct mmc_queue *mq, struct request *req)
 {
         struct mmc_blk_data *md = mq->data;
+        struct mmc_card *card = md->queue.card;
+        int ret = 0;
+
+        ret = mmc_flush_cache(card);
+        if (ret)
+                ret = -EIO;
 
-        /*
-         * No-op, only service this because we need REQ_FUA for reliable
-         * writes.
-         */
         spin_lock_irq(&md->lock);
-        __blk_end_request_all(req, 0);
+        __blk_end_request_all(req, ret);
         spin_unlock_irq(&md->lock);
 
-        return 1;
+        return ret ? 0 : 1;
 }
 
 /*