---

yaml
---
r: 358655
b: refs/heads/master
c: 2220eed
h: refs/heads/master
i:
  358653: 0461e49
  358651: 45c0d8d
  358647: c0be85f
  358639: 47bc829
  358623: 3062a85
  358591: 4d67324
  358527: 25b9d4c
  358399: 13c6cfd
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 369d321ed1baa7748e770aaaae4d8effad699633
+refs/heads/master: 2220eedfd7aea69008173a224975e10284fbe854

trunk/drivers/mmc/card/block.c

@@ -113,17 +113,6 @@ struct mmc_blk_data {
 
 static DEFINE_MUTEX(open_lock);
 
-enum mmc_blk_status {
-	MMC_BLK_SUCCESS = 0,
-	MMC_BLK_PARTIAL,
-	MMC_BLK_CMD_ERR,
-	MMC_BLK_RETRY,
-	MMC_BLK_ABORT,
-	MMC_BLK_DATA_ERR,
-	MMC_BLK_ECC_ERR,
-	MMC_BLK_NOMEDIUM,
-};
-
 module_param(perdev_minors, int, 0444);
 MODULE_PARM_DESC(perdev_minors, "Minors numbers to allocate per device");
 
@@ -1364,8 +1353,11 @@ static int mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *rqc)
 		} else
 			areq = NULL;
 		areq = mmc_start_req(card->host, areq, (int *) &status);
-		if (!areq)
+		if (!areq) {
+			if (status == MMC_BLK_NEW_REQUEST)
+				mq->flags |= MMC_QUEUE_NEW_REQUEST;
 			return 0;
+		}
 
 		mq_rq = container_of(areq, struct mmc_queue_req, mmc_active);
 		brq = &mq_rq->brq;
@@ -1438,6 +1430,10 @@ static int mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *rqc)
 			break;
 		case MMC_BLK_NOMEDIUM:
 			goto cmd_abort;
+		default:
+			pr_err("%s: Unhandled return value (%d)",
+					req->rq_disk->disk_name, status);
+			goto cmd_abort;
 		}
 
 		if (ret) {
@@ -1472,6 +1468,8 @@ static int mmc_blk_issue_rq(struct mmc_queue *mq, struct request *req)
 	int ret;
 	struct mmc_blk_data *md = mq->data;
 	struct mmc_card *card = md->queue.card;
+	struct mmc_host *host = card->host;
+	unsigned long flags;
 
 	if (req && !mq->mqrq_prev->req)
 		/* claim host only for the first request */
@@ -1486,6 +1484,7 @@ static int mmc_blk_issue_rq(struct mmc_queue *mq, struct request *req)
 		goto out;
 	}
 
+	mq->flags &= ~MMC_QUEUE_NEW_REQUEST;
 	if (req && req->cmd_flags & REQ_DISCARD) {
 		/* complete ongoing async transfer before issuing discard */
 		if (card->host->areq)
@@ -1501,11 +1500,16 @@ static int mmc_blk_issue_rq(struct mmc_queue *mq, struct request *req)
 			mmc_blk_issue_rw_rq(mq, NULL);
 		ret = mmc_blk_issue_flush(mq, req);
 	} else {
+		if (!req && host->areq) {
+			spin_lock_irqsave(&host->context_info.lock, flags);
+			host->context_info.is_waiting_last_req = true;
+			spin_unlock_irqrestore(&host->context_info.lock, flags);
+		}
 		ret = mmc_blk_issue_rw_rq(mq, req);
 	}
 
 out:
-	if (!req)
+	if (!req && !(mq->flags & MMC_QUEUE_NEW_REQUEST))
 		/* release host only when there are no more requests */
 		mmc_release_host(card->host);
 	return ret;

trunk/drivers/mmc/card/queue.c

@@ -22,7 +22,6 @@
 
 #define MMC_QUEUE_BOUNCESZ	65536
 
-#define MMC_QUEUE_SUSPENDED	(1 << 0)
 
 #define MMC_REQ_SPECIAL_MASK	(REQ_DISCARD | REQ_FLUSH)
 
@@ -72,6 +71,10 @@ static int mmc_queue_thread(void *d)
 			set_current_state(TASK_RUNNING);
 			cmd_flags = req ? req->cmd_flags : 0;
 			mq->issue_fn(mq, req);
+			if (mq->flags & MMC_QUEUE_NEW_REQUEST) {
+				mq->flags &= ~MMC_QUEUE_NEW_REQUEST;
+				continue; /* fetch again */
+			}
 
 			/*
 			 * Current request becomes previous request
@@ -113,6 +116,8 @@ static void mmc_request_fn(struct request_queue *q)
 {
 	struct mmc_queue *mq = q->queuedata;
 	struct request *req;
+	unsigned long flags;
+	struct mmc_context_info *cntx;
 
 	if (!mq) {
 		while ((req = blk_fetch_request(q)) != NULL) {
@@ -122,7 +127,20 @@ static void mmc_request_fn(struct request_queue *q)
 		return;
 	}
 
-	if (!mq->mqrq_cur->req && !mq->mqrq_prev->req)
+	cntx = &mq->card->host->context_info;
+	if (!mq->mqrq_cur->req && mq->mqrq_prev->req) {
+		/*
+		 * New MMC request arrived when MMC thread may be
+		 * blocked on the previous request to be complete
+		 * with no current request fetched
+		 */
+		spin_lock_irqsave(&cntx->lock, flags);
+		if (cntx->is_waiting_last_req) {
+			cntx->is_new_req = true;
+			wake_up_interruptible(&cntx->wait);
+		}
+		spin_unlock_irqrestore(&cntx->lock, flags);
+	} else if (!mq->mqrq_cur->req && !mq->mqrq_prev->req)
 		wake_up_process(mq->thread);
 }
 

trunk/drivers/mmc/card/queue.h

@@ -27,6 +27,9 @@ struct mmc_queue {
 	struct task_struct	*thread;
 	struct semaphore	thread_sem;
 	unsigned int		flags;
+#define MMC_QUEUE_SUSPENDED	(1 << 0)
+#define MMC_QUEUE_NEW_REQUEST	(1 << 1)
+
 	int			(*issue_fn)(struct mmc_queue *, struct request *);
 	void			*data;
 	struct request_queue	*queue;

trunk/drivers/mmc/core/bus.c

@@ -321,6 +321,7 @@ int mmc_add_card(struct mmc_card *card)
 #ifdef CONFIG_DEBUG_FS
 	mmc_add_card_debugfs(card);
 #endif
+	mmc_init_context_info(card->host);
 
 	ret = device_add(&card->dev);
 	if (ret)

trunk/drivers/mmc/core/core.c

@@ -319,11 +319,44 @@ void mmc_start_bkops(struct mmc_card *card, bool from_exception)
 }
 EXPORT_SYMBOL(mmc_start_bkops);
 
+/*
+ * mmc_wait_data_done() - done callback for data request
+ * @mrq: done data request
+ *
+ * Wakes up mmc context, passed as a callback to host controller driver
+ */
+static void mmc_wait_data_done(struct mmc_request *mrq)
+{
+	mrq->host->context_info.is_done_rcv = true;
+	wake_up_interruptible(&mrq->host->context_info.wait);
+}
+
 static void mmc_wait_done(struct mmc_request *mrq)
 {
 	complete(&mrq->completion);
 }
 
+/*
+ *__mmc_start_data_req() - starts data request
+ * @host: MMC host to start the request
+ * @mrq: data request to start
+ *
+ * Sets the done callback to be called when request is completed by the card.
+ * Starts data mmc request execution
+ */
+static int __mmc_start_data_req(struct mmc_host *host, struct mmc_request *mrq)
+{
+	mrq->done = mmc_wait_data_done;
+	mrq->host = host;
+	if (mmc_card_removed(host->card)) {
+		mrq->cmd->error = -ENOMEDIUM;
+		return -ENOMEDIUM;
+	}
+	mmc_start_request(host, mrq);
+
+	return 0;
+}
+
 static int __mmc_start_req(struct mmc_host *host, struct mmc_request *mrq)
 {
 	init_completion(&mrq->completion);
@@ -337,6 +370,62 @@ static int __mmc_start_req(struct mmc_host *host, struct mmc_request *mrq)
 	return 0;
 }
 
+/*
+ * mmc_wait_for_data_req_done() - wait for request completed
+ * @host: MMC host to prepare the command.
+ * @mrq: MMC request to wait for
+ *
+ * Blocks MMC context till host controller will ack end of data request
+ * execution or new request notification arrives from the block layer.
+ * Handles command retries.
+ *
+ * Returns enum mmc_blk_status after checking errors.
+ */
+static int mmc_wait_for_data_req_done(struct mmc_host *host,
+				      struct mmc_request *mrq,
+				      struct mmc_async_req *next_req)
+{
+	struct mmc_command *cmd;
+	struct mmc_context_info *context_info = &host->context_info;
+	int err;
+	unsigned long flags;
+
+	while (1) {
+		wait_event_interruptible(context_info->wait,
+				(context_info->is_done_rcv ||
+				 context_info->is_new_req));
+		spin_lock_irqsave(&context_info->lock, flags);
+		context_info->is_waiting_last_req = false;
+		spin_unlock_irqrestore(&context_info->lock, flags);
+		if (context_info->is_done_rcv) {
+			context_info->is_done_rcv = false;
+			context_info->is_new_req = false;
+			cmd = mrq->cmd;
+			if (!cmd->error || !cmd->retries ||
+			    mmc_card_removed(host->card)) {
+				err = host->areq->err_check(host->card,
+							    host->areq);
+				break; /* return err */
+			} else {
+				pr_info("%s: req failed (CMD%u): %d, retrying...\n",
+					mmc_hostname(host),
+					cmd->opcode, cmd->error);
+				cmd->retries--;
+				cmd->error = 0;
+				host->ops->request(host, mrq);
+				continue; /* wait for done/new event again */
+			}
+		} else if (context_info->is_new_req) {
+			context_info->is_new_req = false;
+			if (!next_req) {
+				err = MMC_BLK_NEW_REQUEST;
+				break; /* return err */
+			}
+		}
+	}
+	return err;
+}
+
 static void mmc_wait_for_req_done(struct mmc_host *host,
 				  struct mmc_request *mrq)
 {
@@ -426,8 +515,17 @@ struct mmc_async_req *mmc_start_req(struct mmc_host *host,
 		mmc_pre_req(host, areq->mrq, !host->areq);
 
 	if (host->areq) {
-		mmc_wait_for_req_done(host, host->areq->mrq);
-		err = host->areq->err_check(host->card, host->areq);
+			err = mmc_wait_for_data_req_done(host, host->areq->mrq,
+					areq);
+			if (err == MMC_BLK_NEW_REQUEST) {
+				if (error)
+					*error = err;
+				/*
+				 * The previous request was not completed,
+				 * nothing to return
+				 */
+				return NULL;
+			}
 		/*
 		 * Check BKOPS urgency for each R1 response
 		 */
@@ -439,7 +537,7 @@ struct mmc_async_req *mmc_start_req(struct mmc_host *host,
 	}
 
 	if (!err && areq)
-		start_err = __mmc_start_req(host, areq->mrq);
+		start_err = __mmc_start_data_req(host, areq->mrq);
 
 	if (host->areq)
 		mmc_post_req(host, host->areq->mrq, 0);
@@ -2581,6 +2679,23 @@ int mmc_pm_notify(struct notifier_block *notify_block,
 }
 #endif
 
+/**
+ * mmc_init_context_info() - init synchronization context
+ * @host: mmc host
+ *
+ * Init struct context_info needed to implement asynchronous
+ * request mechanism, used by mmc core, host driver and mmc requests
+ * supplier.
+ */
+void mmc_init_context_info(struct mmc_host *host)
+{
+	spin_lock_init(&host->context_info.lock);
+	host->context_info.is_new_req = false;
+	host->context_info.is_done_rcv = false;
+	host->context_info.is_waiting_last_req = false;
+	init_waitqueue_head(&host->context_info.wait);
+}
+
 static int __init mmc_init(void)
 {
 	int ret;

trunk/drivers/mmc/core/core.h

@@ -76,5 +76,6 @@ void mmc_remove_host_debugfs(struct mmc_host *host);
 void mmc_add_card_debugfs(struct mmc_card *card);
 void mmc_remove_card_debugfs(struct mmc_card *card);
 
+void mmc_init_context_info(struct mmc_host *host);
 #endif
 

trunk/include/linux/mmc/card.h

@@ -187,6 +187,18 @@ struct sdio_func_tuple;
 
 #define SDIO_MAX_FUNCS		7
 
+enum mmc_blk_status {
+	MMC_BLK_SUCCESS = 0,
+	MMC_BLK_PARTIAL,
+	MMC_BLK_CMD_ERR,
+	MMC_BLK_RETRY,
+	MMC_BLK_ABORT,
+	MMC_BLK_DATA_ERR,
+	MMC_BLK_ECC_ERR,
+	MMC_BLK_NOMEDIUM,
+	MMC_BLK_NEW_REQUEST,
+};
+
 /* The number of MMC physical partitions.  These consist of:
  * boot partitions (2), general purpose partitions (4) in MMC v4.4.
  */

trunk/include/linux/mmc/core.h

@@ -120,6 +120,7 @@ struct mmc_data {
 	s32			host_cookie;	/* host private data */
 };
 
+struct mmc_host;
 struct mmc_request {
 	struct mmc_command	*sbc;		/* SET_BLOCK_COUNT for multiblock */
 	struct mmc_command	*cmd;
@@ -128,9 +129,9 @@ struct mmc_request {
 
 	struct completion	completion;
 	void			(*done)(struct mmc_request *);/* completion function */
+	struct mmc_host		*host;
 };
 
-struct mmc_host;
 struct mmc_card;
 struct mmc_async_req;
 

trunk/include/linux/mmc/host.h

@@ -170,6 +170,22 @@ struct mmc_slot {
 	void *handler_priv;
 };
 
+/**
+ * mmc_context_info - synchronization details for mmc context
+ * @is_done_rcv		wake up reason was done request
+ * @is_new_req		wake up reason was new request
+ * @is_waiting_last_req	mmc context waiting for single running request
+ * @wait		wait queue
+ * @lock		lock to protect data fields
+ */
+struct mmc_context_info {
+	bool			is_done_rcv;
+	bool			is_new_req;
+	bool			is_waiting_last_req;
+	wait_queue_head_t	wait;
+	spinlock_t		lock;
+};
+
 struct regulator;
 
 struct mmc_supply {
@@ -331,6 +347,7 @@ struct mmc_host {
 	struct dentry		*debugfs_root;
 
 	struct mmc_async_req	*areq;		/* active async req */
+	struct mmc_context_info	context_info;	/* async synchronization info */
 
 #ifdef CONFIG_FAIL_MMC_REQUEST
 	struct fault_attr	fail_mmc_request;