1 files changed, 464 insertions, 217 deletions

diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
index f85e42224559..1ff5486213fb 100644
--- a/drivers/mmc/card/block.c
+++ b/drivers/mmc/card/block.c
@@ -106,6 +106,16 @@ struct mmc_blk_data {
 
 static DEFINE_MUTEX(open_lock);
 
+enum mmc_blk_status {
+	MMC_BLK_SUCCESS = 0,
+	MMC_BLK_PARTIAL,
+	MMC_BLK_RETRY,
+	MMC_BLK_RETRY_SINGLE,
+	MMC_BLK_DATA_ERR,
+	MMC_BLK_CMD_ERR,
+	MMC_BLK_ABORT,
+};
+
 module_param(perdev_minors, int, 0444);
 MODULE_PARM_DESC(perdev_minors, "Minors numbers to allocate per device");
 
@@ -427,14 +437,6 @@ static const struct block_device_operations mmc_bdops = {
 #endif
 };
 
-struct mmc_blk_request {
-	struct mmc_request	mrq;
-	struct mmc_command	sbc;
-	struct mmc_command	cmd;
-	struct mmc_command	stop;
-	struct mmc_data		data;
-};
-
 static inline int mmc_blk_part_switch(struct mmc_card *card,
 				      struct mmc_blk_data *md)
 {
@@ -525,7 +527,20 @@ static u32 mmc_sd_num_wr_blocks(struct mmc_card *card)
 	return result;
 }
 
-static u32 get_card_status(struct mmc_card *card, struct request *req)
+static int send_stop(struct mmc_card *card, u32 *status)
+{
+	struct mmc_command cmd = {0};
+	int err;
+
+	cmd.opcode = MMC_STOP_TRANSMISSION;
+	cmd.flags = MMC_RSP_SPI_R1B | MMC_RSP_R1B | MMC_CMD_AC;
+	err = mmc_wait_for_cmd(card->host, &cmd, 5);
+	if (err == 0)
+		*status = cmd.resp[0];
+	return err;
+}
+
+static int get_card_status(struct mmc_card *card, u32 *status, int retries)
 {
 	struct mmc_command cmd = {0};
 	int err;
@@ -534,11 +549,141 @@ static u32 get_card_status(struct mmc_card *card, struct request *req)
 	if (!mmc_host_is_spi(card->host))
 		cmd.arg = card->rca << 16;
 	cmd.flags = MMC_RSP_SPI_R2 | MMC_RSP_R1 | MMC_CMD_AC;
-	err = mmc_wait_for_cmd(card->host, &cmd, 0);
+	err = mmc_wait_for_cmd(card->host, &cmd, retries);
+	if (err == 0)
+		*status = cmd.resp[0];
+	return err;
+}
+
+#define ERR_RETRY	2
+#define ERR_ABORT	1
+#define ERR_CONTINUE	0
+
+static int mmc_blk_cmd_error(struct request *req, const char *name, int error,
+	bool status_valid, u32 status)
+{
+	switch (error) {
+	case -EILSEQ:
+		/* response crc error, retry the r/w cmd */
+		pr_err("%s: %s sending %s command, card status %#x\n",
+			req->rq_disk->disk_name, "response CRC error",
+			name, status);
+		return ERR_RETRY;
+
+	case -ETIMEDOUT:
+		pr_err("%s: %s sending %s command, card status %#x\n",
+			req->rq_disk->disk_name, "timed out", name, status);
+
+		/* If the status cmd initially failed, retry the r/w cmd */
+		if (!status_valid)
+			return ERR_RETRY;
+
+		/*
+		 * If it was a r/w cmd crc error, or illegal command
+		 * (eg, issued in wrong state) then retry - we should
+		 * have corrected the state problem above.
+		 */
+		if (status & (R1_COM_CRC_ERROR | R1_ILLEGAL_COMMAND))
+			return ERR_RETRY;
+
+		/* Otherwise abort the command */
+		return ERR_ABORT;
+
+	default:
+		/* We don't understand the error code the driver gave us */
+		pr_err("%s: unknown error %d sending read/write command, card status %#x\n",
+		       req->rq_disk->disk_name, error, status);
+		return ERR_ABORT;
+	}
+}
+
+/*
+ * Initial r/w and stop cmd error recovery.
+ * We don't know whether the card received the r/w cmd or not, so try to
+ * restore things back to a sane state.  Essentially, we do this as follows:
+ * - Obtain card status.  If the first attempt to obtain card status fails,
+ *   the status word will reflect the failed status cmd, not the failed
+ *   r/w cmd.  If we fail to obtain card status, it suggests we can no
+ *   longer communicate with the card.
+ * - Check the card state.  If the card received the cmd but there was a
+ *   transient problem with the response, it might still be in a data transfer
+ *   mode.  Try to send it a stop command.  If this fails, we can't recover.
+ * - If the r/w cmd failed due to a response CRC error, it was probably
+ *   transient, so retry the cmd.
+ * - If the r/w cmd timed out, but we didn't get the r/w cmd status, retry.
+ * - If the r/w cmd timed out, and the r/w cmd failed due to CRC error or
+ *   illegal cmd, retry.
+ * Otherwise we don't understand what happened, so abort.
+ */
+static int mmc_blk_cmd_recovery(struct mmc_card *card, struct request *req,
+	struct mmc_blk_request *brq)
+{
+	bool prev_cmd_status_valid = true;
+	u32 status, stop_status = 0;
+	int err, retry;
+
+	/*
+	 * Try to get card status which indicates both the card state
+	 * and why there was no response.  If the first attempt fails,
+	 * we can't be sure the returned status is for the r/w command.
+	 */
+	for (retry = 2; retry >= 0; retry--) {
+		err = get_card_status(card, &status, 0);
+		if (!err)
+			break;
+
+		prev_cmd_status_valid = false;
+		pr_err("%s: error %d sending status command, %sing\n",
+		       req->rq_disk->disk_name, err, retry ? "retry" : "abort");
+	}
+
+	/* We couldn't get a response from the card.  Give up. */
 	if (err)
-		printk(KERN_ERR "%s: error %d sending status command",
-		       req->rq_disk->disk_name, err);
-	return cmd.resp[0];
+		return ERR_ABORT;
+
+	/*
+	 * Check the current card state.  If it is in some data transfer
+	 * mode, tell it to stop (and hopefully transition back to TRAN.)
+	 */
+	if (R1_CURRENT_STATE(status) == R1_STATE_DATA ||
+	    R1_CURRENT_STATE(status) == R1_STATE_RCV) {
+		err = send_stop(card, &stop_status);
+		if (err)
+			pr_err("%s: error %d sending stop command\n",
+			       req->rq_disk->disk_name, err);
+
+		/*
+		 * If the stop cmd also timed out, the card is probably
+		 * not present, so abort.  Other errors are bad news too.
+		 */
+		if (err)
+			return ERR_ABORT;
+	}
+
+	/* Check for set block count errors */
+	if (brq->sbc.error)
+		return mmc_blk_cmd_error(req, "SET_BLOCK_COUNT", brq->sbc.error,
+				prev_cmd_status_valid, status);
+
+	/* Check for r/w command errors */
+	if (brq->cmd.error)
+		return mmc_blk_cmd_error(req, "r/w cmd", brq->cmd.error,
+				prev_cmd_status_valid, status);
+
+	/* Now for stop errors.  These aren't fatal to the transfer. */
+	pr_err("%s: error %d sending stop command, original cmd response %#x, card status %#x\n",
+	       req->rq_disk->disk_name, brq->stop.error,
+	       brq->cmd.resp[0], status);
+
+	/*
+	 * Subsitute in our own stop status as this will give the error
+	 * state which happened during the execution of the r/w command.
+	 */
+	if (stop_status) {
+		brq->stop.resp[0] = stop_status;
+		brq->stop.error = 0;
+	}
+	return ERR_CONTINUE;
 }
 
 static int mmc_blk_issue_discard_rq(struct mmc_queue *mq, struct request *req)
@@ -669,240 +814,324 @@ static inline void mmc_apply_rel_rw(struct mmc_blk_request *brq,
 	}
 }
 
-static int mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *req)
+#define CMD_ERRORS							\
+	(R1_OUT_OF_RANGE |	/* Command argument out of range */	\
+	 R1_ADDRESS_ERROR |	/* Misaligned address */		\
+	 R1_BLOCK_LEN_ERROR |	/* Transferred block length incorrect */\
+	 R1_WP_VIOLATION |	/* Tried to write to protected block */	\
+	 R1_CC_ERROR |		/* Card controller error */		\
+	 R1_ERROR)		/* General/unknown error */
+
+static int mmc_blk_err_check(struct mmc_card *card,
+			     struct mmc_async_req *areq)
 {
-	struct mmc_blk_data *md = mq->data;
-	struct mmc_card *card = md->queue.card;
-	struct mmc_blk_request brq;
-	int ret = 1, disable_multi = 0;
+	enum mmc_blk_status ret = MMC_BLK_SUCCESS;
+	struct mmc_queue_req *mq_mrq = container_of(areq, struct mmc_queue_req,
+						    mmc_active);
+	struct mmc_blk_request *brq = &mq_mrq->brq;
+	struct request *req = mq_mrq->req;
 
 	/*
-	 * Reliable writes are used to implement Forced Unit Access and
-	 * REQ_META accesses, and are supported only on MMCs.
+	 * sbc.error indicates a problem with the set block count
+	 * command.  No data will have been transferred.
+	 *
+	 * cmd.error indicates a problem with the r/w command.  No
+	 * data will have been transferred.
+	 *
+	 * stop.error indicates a problem with the stop command.  Data
+	 * may have been transferred, or may still be transferring.
 	 */
-	bool do_rel_wr = ((req->cmd_flags & REQ_FUA) ||
-			  (req->cmd_flags & REQ_META)) &&
-		(rq_data_dir(req) == WRITE) &&
-		(md->flags & MMC_BLK_REL_WR);
+	if (brq->sbc.error || brq->cmd.error || brq->stop.error) {
+		switch (mmc_blk_cmd_recovery(card, req, brq)) {
+		case ERR_RETRY:
+			return MMC_BLK_RETRY;
+		case ERR_ABORT:
+			return MMC_BLK_ABORT;
+		case ERR_CONTINUE:
+			break;
+		}
+	}
 
-	do {
-		struct mmc_command cmd = {0};
-		u32 readcmd, writecmd, status = 0;
-
-		memset(&brq, 0, sizeof(struct mmc_blk_request));
-		brq.mrq.cmd = &brq.cmd;
-		brq.mrq.data = &brq.data;
-
-		brq.cmd.arg = blk_rq_pos(req);
-		if (!mmc_card_blockaddr(card))
-			brq.cmd.arg <<= 9;
-		brq.cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 | MMC_CMD_ADTC;
-		brq.data.blksz = 512;
-		brq.stop.opcode = MMC_STOP_TRANSMISSION;
-		brq.stop.arg = 0;
-		brq.stop.flags = MMC_RSP_SPI_R1B | MMC_RSP_R1B | MMC_CMD_AC;
-		brq.data.blocks = blk_rq_sectors(req);
+	/*
+	 * Check for errors relating to the execution of the
+	 * initial command - such as address errors.  No data
+	 * has been transferred.
+	 */
+	if (brq->cmd.resp[0] & CMD_ERRORS) {
+		pr_err("%s: r/w command failed, status = %#x\n",
+		       req->rq_disk->disk_name, brq->cmd.resp[0]);
+		return MMC_BLK_ABORT;
+	}
 
-		/*
-		 * The block layer doesn't support all sector count
-		 * restrictions, so we need to be prepared for too big
-		 * requests.
-		 */
-		if (brq.data.blocks > card->host->max_blk_count)
-			brq.data.blocks = card->host->max_blk_count;
+	/*
+	 * Everything else is either success, or a data error of some
+	 * kind.  If it was a write, we may have transitioned to
+	 * program mode, which we have to wait for it to complete.
+	 */
+	if (!mmc_host_is_spi(card->host) && rq_data_dir(req) != READ) {
+		u32 status;
+		do {
+			int err = get_card_status(card, &status, 5);
+			if (err) {
+				printk(KERN_ERR "%s: error %d requesting status\n",
+				       req->rq_disk->disk_name, err);
+				return MMC_BLK_CMD_ERR;
+			}
+			/*
+			 * Some cards mishandle the status bits,
+			 * so make sure to check both the busy
+			 * indication and the card state.
+			 */
+		} while (!(status & R1_READY_FOR_DATA) ||
+			 (R1_CURRENT_STATE(status) == R1_STATE_PRG));
+	}
 
-		/*
-		 * After a read error, we redo the request one sector at a time
-		 * in order to accurately determine which sectors can be read
-		 * successfully.
-		 */
-		if (disable_multi && brq.data.blocks > 1)
-			brq.data.blocks = 1;
+	if (brq->data.error) {
+		pr_err("%s: error %d transferring data, sector %u, nr %u, cmd response %#x, card status %#x\n",
+		       req->rq_disk->disk_name, brq->data.error,
+		       (unsigned)blk_rq_pos(req),
+		       (unsigned)blk_rq_sectors(req),
+		       brq->cmd.resp[0], brq->stop.resp[0]);
 
-		if (brq.data.blocks > 1 || do_rel_wr) {
-			/* SPI multiblock writes terminate using a special
-			 * token, not a STOP_TRANSMISSION request.
-			 */
-			if (!mmc_host_is_spi(card->host) ||
-			    rq_data_dir(req) == READ)
-				brq.mrq.stop = &brq.stop;
-			readcmd = MMC_READ_MULTIPLE_BLOCK;
-			writecmd = MMC_WRITE_MULTIPLE_BLOCK;
-		} else {
-			brq.mrq.stop = NULL;
-			readcmd = MMC_READ_SINGLE_BLOCK;
-			writecmd = MMC_WRITE_BLOCK;
-		}
 		if (rq_data_dir(req) == READ) {
-			brq.cmd.opcode = readcmd;
-			brq.data.flags |= MMC_DATA_READ;
+			if (brq->data.blocks > 1) {
+				/* Redo read one sector at a time */
+				pr_warning("%s: retrying using single block read\n",
+					   req->rq_disk->disk_name);
+				return MMC_BLK_RETRY_SINGLE;
+			}
+			return MMC_BLK_DATA_ERR;
 		} else {
-			brq.cmd.opcode = writecmd;
-			brq.data.flags |= MMC_DATA_WRITE;
+			return MMC_BLK_CMD_ERR;
 		}
+	}
 
-		if (do_rel_wr)
-			mmc_apply_rel_rw(&brq, card, req);
+	if (ret == MMC_BLK_SUCCESS &&
+	    blk_rq_bytes(req) != brq->data.bytes_xfered)
+		ret = MMC_BLK_PARTIAL;
 
-		/*
-		 * Pre-defined multi-block transfers are preferable to
-		 * open ended-ones (and necessary for reliable writes).
-		 * However, it is not sufficient to just send CMD23,
-		 * and avoid the final CMD12, as on an error condition
-		 * CMD12 (stop) needs to be sent anyway. This, coupled
-		 * with Auto-CMD23 enhancements provided by some
-		 * hosts, means that the complexity of dealing
-		 * with this is best left to the host. If CMD23 is
-		 * supported by card and host, we'll fill sbc in and let
-		 * the host deal with handling it correctly. This means
-		 * that for hosts that don't expose MMC_CAP_CMD23, no
-		 * change of behavior will be observed.
-		 *
-		 * N.B: Some MMC cards experience perf degradation.
-		 * We'll avoid using CMD23-bounded multiblock writes for
-		 * these, while retaining features like reliable writes.
-		 */
+	return ret;
+}
 
-		if ((md->flags & MMC_BLK_CMD23) &&
-		    mmc_op_multi(brq.cmd.opcode) &&
-		    (do_rel_wr || !(card->quirks & MMC_QUIRK_BLK_NO_CMD23))) {
-			brq.sbc.opcode = MMC_SET_BLOCK_COUNT;
-			brq.sbc.arg = brq.data.blocks |
-				(do_rel_wr ? (1 << 31) : 0);
-			brq.sbc.flags = MMC_RSP_R1 | MMC_CMD_AC;
-			brq.mrq.sbc = &brq.sbc;
-		}
+static void mmc_blk_rw_rq_prep(struct mmc_queue_req *mqrq,
+			       struct mmc_card *card,
+			       int disable_multi,
+			       struct mmc_queue *mq)
+{
+	u32 readcmd, writecmd;
+	struct mmc_blk_request *brq = &mqrq->brq;
+	struct request *req = mqrq->req;
+	struct mmc_blk_data *md = mq->data;
 
-		mmc_set_data_timeout(&brq.data, card);
+	/*
+	 * Reliable writes are used to implement Forced Unit Access and
+	 * REQ_META accesses, and are supported only on MMCs.
+	 */
+	bool do_rel_wr = ((req->cmd_flags & REQ_FUA) ||
+			  (req->cmd_flags & REQ_META)) &&
+		(rq_data_dir(req) == WRITE) &&
+		(md->flags & MMC_BLK_REL_WR);
 
-		brq.data.sg = mq->sg;
-		brq.data.sg_len = mmc_queue_map_sg(mq);
+	memset(brq, 0, sizeof(struct mmc_blk_request));
+	brq->mrq.cmd = &brq->cmd;
+	brq->mrq.data = &brq->data;
 
-		/*
-		 * Adjust the sg list so it is the same size as the
-		 * request.
+	brq->cmd.arg = blk_rq_pos(req);
+	if (!mmc_card_blockaddr(card))
+		brq->cmd.arg <<= 9;
+	brq->cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 | MMC_CMD_ADTC;
+	brq->data.blksz = 512;
+	brq->stop.opcode = MMC_STOP_TRANSMISSION;
+	brq->stop.arg = 0;
+	brq->stop.flags = MMC_RSP_SPI_R1B | MMC_RSP_R1B | MMC_CMD_AC;
+	brq->data.blocks = blk_rq_sectors(req);
+
+	/*
+	 * The block layer doesn't support all sector count
+	 * restrictions, so we need to be prepared for too big
+	 * requests.
+	 */
+	if (brq->data.blocks > card->host->max_blk_count)
+		brq->data.blocks = card->host->max_blk_count;
+
+	/*
+	 * After a read error, we redo the request one sector at a time
+	 * in order to accurately determine which sectors can be read
+	 * successfully.
+	 */
+	if (disable_multi && brq->data.blocks > 1)
+		brq->data.blocks = 1;
+
+	if (brq->data.blocks > 1 || do_rel_wr) {
+		/* SPI multiblock writes terminate using a special
+		 * token, not a STOP_TRANSMISSION request.
 		 */
-		if (brq.data.blocks != blk_rq_sectors(req)) {
-			int i, data_size = brq.data.blocks << 9;
-			struct scatterlist *sg;
-
-			for_each_sg(brq.data.sg, sg, brq.data.sg_len, i) {
-				data_size -= sg->length;
-				if (data_size <= 0) {
-					sg->length += data_size;
-					i++;
-					break;
-				}
-			}
-			brq.data.sg_len = i;
-		}
+		if (!mmc_host_is_spi(card->host) ||
+		    rq_data_dir(req) == READ)
+			brq->mrq.stop = &brq->stop;
+		readcmd = MMC_READ_MULTIPLE_BLOCK;
+		writecmd = MMC_WRITE_MULTIPLE_BLOCK;
+	} else {
+		brq->mrq.stop = NULL;
+		readcmd = MMC_READ_SINGLE_BLOCK;
+		writecmd = MMC_WRITE_BLOCK;
+	}
+	if (rq_data_dir(req) == READ) {
+		brq->cmd.opcode = readcmd;
+		brq->data.flags |= MMC_DATA_READ;
+	} else {
+		brq->cmd.opcode = writecmd;
+		brq->data.flags |= MMC_DATA_WRITE;
+	}
 
-		mmc_queue_bounce_pre(mq);
+	if (do_rel_wr)
+		mmc_apply_rel_rw(brq, card, req);
 
-		mmc_wait_for_req(card->host, &brq.mrq);
+	/*
+	 * Pre-defined multi-block transfers are preferable to
+	 * open ended-ones (and necessary for reliable writes).
+	 * However, it is not sufficient to just send CMD23,
+	 * and avoid the final CMD12, as on an error condition
+	 * CMD12 (stop) needs to be sent anyway. This, coupled
+	 * with Auto-CMD23 enhancements provided by some
+	 * hosts, means that the complexity of dealing
+	 * with this is best left to the host. If CMD23 is
+	 * supported by card and host, we'll fill sbc in and let
+	 * the host deal with handling it correctly. This means
+	 * that for hosts that don't expose MMC_CAP_CMD23, no
+	 * change of behavior will be observed.
+	 *
+	 * N.B: Some MMC cards experience perf degradation.
+	 * We'll avoid using CMD23-bounded multiblock writes for
+	 * these, while retaining features like reliable writes.
+	 */
 
-		mmc_queue_bounce_post(mq);
+	if ((md->flags & MMC_BLK_CMD23) &&
+	    mmc_op_multi(brq->cmd.opcode) &&
+	    (do_rel_wr || !(card->quirks & MMC_QUIRK_BLK_NO_CMD23))) {
+		brq->sbc.opcode = MMC_SET_BLOCK_COUNT;
+		brq->sbc.arg = brq->data.blocks |
+			(do_rel_wr ? (1 << 31) : 0);
+		brq->sbc.flags = MMC_RSP_R1 | MMC_CMD_AC;
+		brq->mrq.sbc = &brq->sbc;
+	}
 
-		/*
-		 * Check for errors here, but don't jump to cmd_err
-		 * until later as we need to wait for the card to leave
-		 * programming mode even when things go wrong.
-		 */
-		if (brq.sbc.error || brq.cmd.error ||
-		    brq.data.error || brq.stop.error) {
-			if (brq.data.blocks > 1 && rq_data_dir(req) == READ) {
-				/* Redo read one sector at a time */
-				printk(KERN_WARNING "%s: retrying using single "
-				       "block read\n", req->rq_disk->disk_name);
-				disable_multi = 1;
-				continue;
-			}
-			status = get_card_status(card, req);
-		}
+	mmc_set_data_timeout(&brq->data, card);
 
-		if (brq.sbc.error) {
-			printk(KERN_ERR "%s: error %d sending SET_BLOCK_COUNT "
-			       "command, response %#x, card status %#x\n",
-			       req->rq_disk->disk_name, brq.sbc.error,
-			       brq.sbc.resp[0], status);
-		}
+	brq->data.sg = mqrq->sg;
+	brq->data.sg_len = mmc_queue_map_sg(mq, mqrq);
 
-		if (brq.cmd.error) {
-			printk(KERN_ERR "%s: error %d sending read/write "
-			       "command, response %#x, card status %#x\n",
-			       req->rq_disk->disk_name, brq.cmd.error,
-			       brq.cmd.resp[0], status);
+	/*
+	 * Adjust the sg list so it is the same size as the
+	 * request.
+	 */
+	if (brq->data.blocks != blk_rq_sectors(req)) {
+		int i, data_size = brq->data.blocks << 9;
+		struct scatterlist *sg;
+
+		for_each_sg(brq->data.sg, sg, brq->data.sg_len, i) {
+			data_size -= sg->length;
+			if (data_size <= 0) {
+				sg->length += data_size;
+				i++;
+				break;
+			}
 		}
+		brq->data.sg_len = i;
+	}
 
-		if (brq.data.error) {
-			if (brq.data.error == -ETIMEDOUT && brq.mrq.stop)
-				/* 'Stop' response contains card status */
-				status = brq.mrq.stop->resp[0];
-			printk(KERN_ERR "%s: error %d transferring data,"
-			       " sector %u, nr %u, card status %#x\n",
-			       req->rq_disk->disk_name, brq.data.error,
-			       (unsigned)blk_rq_pos(req),
-			       (unsigned)blk_rq_sectors(req), status);
-		}
+	mqrq->mmc_active.mrq = &brq->mrq;
+	mqrq->mmc_active.err_check = mmc_blk_err_check;
 
-		if (brq.stop.error) {
-			printk(KERN_ERR "%s: error %d sending stop command, "
-			       "response %#x, card status %#x\n",
-			       req->rq_disk->disk_name, brq.stop.error,
-			       brq.stop.resp[0], status);
-		}
+	mmc_queue_bounce_pre(mqrq);
+}
 
-		if (!mmc_host_is_spi(card->host) && rq_data_dir(req) != READ) {
-			do {
-				int err;
-
-				cmd.opcode = MMC_SEND_STATUS;
-				cmd.arg = card->rca << 16;
-				cmd.flags = MMC_RSP_R1 | MMC_CMD_AC;
-				err = mmc_wait_for_cmd(card->host, &cmd, 5);
-				if (err) {
-					printk(KERN_ERR "%s: error %d requesting status\n",
-					       req->rq_disk->disk_name, err);
-					goto cmd_err;
-				}
-				/*
-				 * Some cards mishandle the status bits,
-				 * so make sure to check both the busy
-				 * indication and the card state.
-				 */
-			} while (!(cmd.resp[0] & R1_READY_FOR_DATA) ||
-				(R1_CURRENT_STATE(cmd.resp[0]) == 7));
-
-#if 0
-			if (cmd.resp[0] & ~0x00000900)
-				printk(KERN_ERR "%s: status = %08x\n",
-				       req->rq_disk->disk_name, cmd.resp[0]);
-			if (mmc_decode_status(cmd.resp))
-				goto cmd_err;
-#endif
-		}
+static int mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *rqc)
+{
+	struct mmc_blk_data *md = mq->data;
+	struct mmc_card *card = md->queue.card;
+	struct mmc_blk_request *brq = &mq->mqrq_cur->brq;
+	int ret = 1, disable_multi = 0, retry = 0;
+	enum mmc_blk_status status;
+	struct mmc_queue_req *mq_rq;
+	struct request *req;
+	struct mmc_async_req *areq;
+
+	if (!rqc && !mq->mqrq_prev->req)
+		return 0;
 
-		if (brq.cmd.error || brq.stop.error || brq.data.error) {
-			if (rq_data_dir(req) == READ) {
+	do {
+		if (rqc) {
+			mmc_blk_rw_rq_prep(mq->mqrq_cur, card, 0, mq);
+			areq = &mq->mqrq_cur->mmc_active;
+		} else
+			areq = NULL;
+		areq = mmc_start_req(card->host, areq, (int *) &status);
+		if (!areq)
+			return 0;
+
+		mq_rq = container_of(areq, struct mmc_queue_req, mmc_active);
+		brq = &mq_rq->brq;
+		req = mq_rq->req;
+		mmc_queue_bounce_post(mq_rq);
+
+		switch (status) {
+		case MMC_BLK_SUCCESS:
+		case MMC_BLK_PARTIAL:
+			/*
+			 * A block was successfully transferred.
+			 */
+			spin_lock_irq(&md->lock);
+			ret = __blk_end_request(req, 0,
+						brq->data.bytes_xfered);
+			spin_unlock_irq(&md->lock);
+			if (status == MMC_BLK_SUCCESS && ret) {
 				/*
-				 * After an error, we redo I/O one sector at a
-				 * time, so we only reach here after trying to
-				 * read a single sector.
+				 * The blk_end_request has returned non zero
+				 * even though all data is transfered and no
+				 * erros returned by host.
+				 * If this happen it's a bug.
 				 */
-				spin_lock_irq(&md->lock);
-				ret = __blk_end_request(req, -EIO, brq.data.blksz);
-				spin_unlock_irq(&md->lock);
-				continue;
+				printk(KERN_ERR "%s BUG rq_tot %d d_xfer %d\n",
+				       __func__, blk_rq_bytes(req),
+				       brq->data.bytes_xfered);
+				rqc = NULL;
+				goto cmd_abort;
 			}
+			break;
+		case MMC_BLK_CMD_ERR:
 			goto cmd_err;
+		case MMC_BLK_RETRY_SINGLE:
+			disable_multi = 1;
+			break;
+		case MMC_BLK_RETRY:
+			if (retry++ < 5)
+				break;
+		case MMC_BLK_ABORT:
+			goto cmd_abort;
+		case MMC_BLK_DATA_ERR:
+			/*
+			 * After an error, we redo I/O one sector at a
+			 * time, so we only reach here after trying to
+			 * read a single sector.
+			 */
+			spin_lock_irq(&md->lock);
+			ret = __blk_end_request(req, -EIO,
+						brq->data.blksz);
+			spin_unlock_irq(&md->lock);
+			if (!ret)
+				goto start_new_req;
+			break;
 		}
 
-		/*
-		 * A block was successfully transferred.
-		 */
-		spin_lock_irq(&md->lock);
-		ret = __blk_end_request(req, 0, brq.data.bytes_xfered);
-		spin_unlock_irq(&md->lock);
+		if (ret) {
+			/*
+			 * In case of a none complete request
+			 * prepare it again and resend.
+			 */
+			mmc_blk_rw_rq_prep(mq_rq, card, disable_multi, mq);
+			mmc_start_req(card->host, &mq_rq->mmc_active, NULL);
+		}
 	} while (ret);
 
 	return 1;
@@ -927,15 +1156,22 @@ static int mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *req)
 		}
 	} else {
 		spin_lock_irq(&md->lock);
-		ret = __blk_end_request(req, 0, brq.data.bytes_xfered);
+		ret = __blk_end_request(req, 0, brq->data.bytes_xfered);
 		spin_unlock_irq(&md->lock);
 	}
 
+ cmd_abort:
 	spin_lock_irq(&md->lock);
 	while (ret)
 		ret = __blk_end_request(req, -EIO, blk_rq_cur_bytes(req));
 	spin_unlock_irq(&md->lock);
 
+ start_new_req:
+	if (rqc) {
+		mmc_blk_rw_rq_prep(mq->mqrq_cur, card, 0, mq);
+		mmc_start_req(card->host, &mq->mqrq_cur->mmc_active, NULL);
+	}
+
 	return 0;
 }
 
@@ -945,26 +1181,37 @@ 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;
 
-	mmc_claim_host(card->host);
+	if (req && !mq->mqrq_prev->req)
+		/* claim host only for the first request */
+		mmc_claim_host(card->host);
+
 	ret = mmc_blk_part_switch(card, md);
 	if (ret) {
 		ret = 0;
 		goto out;
 	}
 
-	if (req->cmd_flags & REQ_DISCARD) {
+	if (req && req->cmd_flags & REQ_DISCARD) {
+		/* complete ongoing async transfer before issuing discard */
+		if (card->host->areq)
+			mmc_blk_issue_rw_rq(mq, NULL);
 		if (req->cmd_flags & REQ_SECURE)
 			ret = mmc_blk_issue_secdiscard_rq(mq, req);
 		else
 			ret = mmc_blk_issue_discard_rq(mq, req);
-	} else if (req->cmd_flags & REQ_FLUSH) {
+	} else if (req && req->cmd_flags & REQ_FLUSH) {
+		/* complete ongoing async transfer before issuing flush */
+		if (card->host->areq)
+			mmc_blk_issue_rw_rq(mq, NULL);
 		ret = mmc_blk_issue_flush(mq, req);
 	} else {
 		ret = mmc_blk_issue_rw_rq(mq, req);
 	}
 
 out:
-	mmc_release_host(card->host);
+	if (!req)
+		/* release host only when there are no more requests */
+		mmc_release_host(card->host);
 	return ret;
 }