[PATCH] mmc: properly use the new multi block-write error handling

Use the new multi block-write error reporting flag and properly tell the block
layer how much data was transferred before the error.

Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 17 insertions, 7 deletions

diff --git a/drivers/mmc/mmc_block.c b/drivers/mmc/mmc_block.c
index db0e8ad439a5..c1293f1bda87 100644
--- a/drivers/mmc/mmc_block.c
+++ b/drivers/mmc/mmc_block.c
@@ -158,13 +158,13 @@ static int mmc_blk_issue_rq(struct mmc_queue *mq, struct request *req)
 {
         struct mmc_blk_data *md = mq->data;
         struct mmc_card *card = md->queue.card;
+        struct mmc_blk_request brq;
         int ret;
 
         if (mmc_card_claim_host(card))
                 goto cmd_err;
 
         do {
-                struct mmc_blk_request brq;
                 struct mmc_command cmd;
                 u32 readcmd, writecmd;
 
@@ -278,17 +278,27 @@ static int mmc_blk_issue_rq(struct mmc_queue *mq, struct request *req)
  cmd_err:
         mmc_card_release_host(card);
 
+        ret = 1;
+
         /*
-         * This is a little draconian, but until we get proper
-         * error handling sorted out here, its the best we can
-         * do - especially as some hosts have no idea how much
-         * data was transferred before the error occurred.
+         * For writes and where the host claims to support proper
+         * error reporting, we first ok the successful blocks.
+         *
+         * For reads we just fail the entire chunk as that should
+         * be safe in all cases.
          */
+        if (rq_data_dir(req) != READ &&
+            (card->host->caps & MMC_CAP_MULTIWRITE)) {
+                spin_lock_irq(&md->lock);
+                ret = end_that_request_chunk(req, 1, brq.data.bytes_xfered);
+                spin_unlock_irq(&md->lock);
+        }
+
         spin_lock_irq(&md->lock);
-        do {
+        while (ret) {
                 ret = end_that_request_chunk(req, 0,
                                 req->current_nr_sectors << 9);
-        } while (ret);
+        }
 
         add_disk_randomness(req->rq_disk);
         blkdev_dequeue_request(req);