1 files changed, 112 insertions, 43 deletions

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 8ed7d4bab7be..adaae345b7c1 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -133,9 +133,11 @@ enum {
 /* UFSHCD UIC layer error flags */
 enum {
 	UFSHCD_UIC_DL_PA_INIT_ERROR = (1 << 0), /* Data link layer error */
-	UFSHCD_UIC_NL_ERROR = (1 << 1), /* Network layer error */
-	UFSHCD_UIC_TL_ERROR = (1 << 2), /* Transport Layer error */
-	UFSHCD_UIC_DME_ERROR = (1 << 3), /* DME error */
+	UFSHCD_UIC_DL_NAC_RECEIVED_ERROR = (1 << 1), /* Data link layer error */
+	UFSHCD_UIC_DL_TCx_REPLAY_ERROR = (1 << 2), /* Data link layer error */
+	UFSHCD_UIC_NL_ERROR = (1 << 3), /* Network layer error */
+	UFSHCD_UIC_TL_ERROR = (1 << 4), /* Transport Layer error */
+	UFSHCD_UIC_DME_ERROR = (1 << 5), /* DME error */
 };
 
 /* Interrupt configuration options */
@@ -3465,31 +3467,18 @@ static void ufshcd_uic_cmd_compl(struct ufs_hba *hba, u32 intr_status)
 }
 
 /**
- * ufshcd_transfer_req_compl - handle SCSI and query command completion
+ * __ufshcd_transfer_req_compl - handle SCSI and query command completion
  * @hba: per adapter instance
+ * @completed_reqs: requests to complete
  */
-static void ufshcd_transfer_req_compl(struct ufs_hba *hba)
+static void __ufshcd_transfer_req_compl(struct ufs_hba *hba,
+					unsigned long completed_reqs)
 {
 	struct ufshcd_lrb *lrbp;
 	struct scsi_cmnd *cmd;
-	unsigned long completed_reqs;
-	u32 tr_doorbell;
 	int result;
 	int index;
 
-	/* Resetting interrupt aggregation counters first and reading the
-	 * DOOR_BELL afterward allows us to handle all the completed requests.
-	 * In order to prevent other interrupts starvation the DB is read once
-	 * after reset. The down side of this solution is the possibility of
-	 * false interrupt if device completes another request after resetting
-	 * aggregation and before reading the DB.
-	 */
-	if (ufshcd_is_intr_aggr_allowed(hba))
-		ufshcd_reset_intr_aggr(hba);
-
-	tr_doorbell = ufshcd_readl(hba, REG_UTP_TRANSFER_REQ_DOOR_BELL);
-	completed_reqs = tr_doorbell ^ hba->outstanding_reqs;
-
 	for_each_set_bit(index, &completed_reqs, hba->nutrs) {
 		lrbp = &hba->lrb[index];
 		cmd = lrbp->cmd;
@@ -3519,6 +3508,31 @@ static void ufshcd_transfer_req_compl(struct ufs_hba *hba)
 }
 
 /**
+ * ufshcd_transfer_req_compl - handle SCSI and query command completion
+ * @hba: per adapter instance
+ */
+static void ufshcd_transfer_req_compl(struct ufs_hba *hba)
+{
+	unsigned long completed_reqs;
+	u32 tr_doorbell;
+
+	/* Resetting interrupt aggregation counters first and reading the
+	 * DOOR_BELL afterward allows us to handle all the completed requests.
+	 * In order to prevent other interrupts starvation the DB is read once
+	 * after reset. The down side of this solution is the possibility of
+	 * false interrupt if device completes another request after resetting
+	 * aggregation and before reading the DB.
+	 */
+	if (ufshcd_is_intr_aggr_allowed(hba))
+		ufshcd_reset_intr_aggr(hba);
+
+	tr_doorbell = ufshcd_readl(hba, REG_UTP_TRANSFER_REQ_DOOR_BELL);
+	completed_reqs = tr_doorbell ^ hba->outstanding_reqs;
+
+	__ufshcd_transfer_req_compl(hba, completed_reqs);
+}
+
+/**
  * ufshcd_disable_ee - disable exception event
  * @hba: per-adapter instance
  * @mask: exception event to disable
@@ -3773,6 +3787,13 @@ out:
 	return;
 }
 
+/* Complete requests that have door-bell cleared */
+static void ufshcd_complete_requests(struct ufs_hba *hba)
+{
+	ufshcd_transfer_req_compl(hba);
+	ufshcd_tmc_handler(hba);
+}
+
 /**
  * ufshcd_err_handler - handle UFS errors that require s/w attention
  * @work: pointer to work structure
@@ -3785,6 +3806,7 @@ static void ufshcd_err_handler(struct work_struct *work)
 	u32 err_tm = 0;
 	int err = 0;
 	int tag;
+	bool needs_reset = false;
 
 	hba = container_of(work, struct ufs_hba, eh_work);
 
@@ -3792,40 +3814,75 @@ static void ufshcd_err_handler(struct work_struct *work)
 	ufshcd_hold(hba, false);
 
 	spin_lock_irqsave(hba->host->host_lock, flags);
-	if (hba->ufshcd_state == UFSHCD_STATE_RESET) {
-		spin_unlock_irqrestore(hba->host->host_lock, flags);
+	if (hba->ufshcd_state == UFSHCD_STATE_RESET)
 		goto out;
-	}
 
 	hba->ufshcd_state = UFSHCD_STATE_RESET;
 	ufshcd_set_eh_in_progress(hba);
 
 	/* Complete requests that have door-bell cleared by h/w */
-	ufshcd_transfer_req_compl(hba);
-	ufshcd_tmc_handler(hba);
-	spin_unlock_irqrestore(hba->host->host_lock, flags);
+	ufshcd_complete_requests(hba);
+	if ((hba->saved_err & INT_FATAL_ERRORS) ||
+	    ((hba->saved_err & UIC_ERROR) &&
+	    (hba->saved_uic_err & (UFSHCD_UIC_DL_PA_INIT_ERROR |
+				   UFSHCD_UIC_DL_NAC_RECEIVED_ERROR |
+				   UFSHCD_UIC_DL_TCx_REPLAY_ERROR))))
+		needs_reset = true;
 
+	/*
+	 * if host reset is required then skip clearing the pending
+	 * transfers forcefully because they will automatically get
+	 * cleared after link startup.
+	 */
+	if (needs_reset)
+		goto skip_pending_xfer_clear;
+
+	/* release lock as clear command might sleep */
+	spin_unlock_irqrestore(hba->host->host_lock, flags);
 	/* Clear pending transfer requests */
-	for_each_set_bit(tag, &hba->outstanding_reqs, hba->nutrs)
-		if (ufshcd_clear_cmd(hba, tag))
-			err_xfer |= 1 << tag;
+	for_each_set_bit(tag, &hba->outstanding_reqs, hba->nutrs) {
+		if (ufshcd_clear_cmd(hba, tag)) {
+			err_xfer = true;
+			goto lock_skip_pending_xfer_clear;
+		}
+	}
 
 	/* Clear pending task management requests */
-	for_each_set_bit(tag, &hba->outstanding_tasks, hba->nutmrs)
-		if (ufshcd_clear_tm_cmd(hba, tag))
-			err_tm |= 1 << tag;
+	for_each_set_bit(tag, &hba->outstanding_tasks, hba->nutmrs) {
+		if (ufshcd_clear_tm_cmd(hba, tag)) {
+			err_tm = true;
+			goto lock_skip_pending_xfer_clear;
+		}
+	}
 
-	/* Complete the requests that are cleared by s/w */
+lock_skip_pending_xfer_clear:
 	spin_lock_irqsave(hba->host->host_lock, flags);
-	ufshcd_transfer_req_compl(hba);
-	ufshcd_tmc_handler(hba);
-	spin_unlock_irqrestore(hba->host->host_lock, flags);
 
+	/* Complete the requests that are cleared by s/w */
+	ufshcd_complete_requests(hba);
+
+	if (err_xfer || err_tm)
+		needs_reset = true;
+
+skip_pending_xfer_clear:
 	/* Fatal errors need reset */
-	if (err_xfer || err_tm || (hba->saved_err & INT_FATAL_ERRORS) ||
-			((hba->saved_err & UIC_ERROR) &&
-			 (hba->saved_uic_err & UFSHCD_UIC_DL_PA_INIT_ERROR))) {
+	if (needs_reset) {
+		unsigned long max_doorbells = (1UL << hba->nutrs) - 1;
+
+		/*
+		 * ufshcd_reset_and_restore() does the link reinitialization
+		 * which will need atleast one empty doorbell slot to send the
+		 * device management commands (NOP and query commands).
+		 * If there is no slot empty at this moment then free up last
+		 * slot forcefully.
+		 */
+		if (hba->outstanding_reqs == max_doorbells)
+			__ufshcd_transfer_req_compl(hba,
+						    (1UL << (hba->nutrs - 1)));
+
+		spin_unlock_irqrestore(hba->host->host_lock, flags);
 		err = ufshcd_reset_and_restore(hba);
+		spin_lock_irqsave(hba->host->host_lock, flags);
 		if (err) {
 			dev_err(hba->dev, "%s: reset and restore failed\n",
 					__func__);
@@ -3839,9 +3896,18 @@ static void ufshcd_err_handler(struct work_struct *work)
 		hba->saved_err = 0;
 		hba->saved_uic_err = 0;
 	}
+
+	if (!needs_reset) {
+		hba->ufshcd_state = UFSHCD_STATE_OPERATIONAL;
+		if (hba->saved_err || hba->saved_uic_err)
+			dev_err_ratelimited(hba->dev, "%s: exit: saved_err 0x%x saved_uic_err 0x%x",
+			    __func__, hba->saved_err, hba->saved_uic_err);
+	}
+
 	ufshcd_clear_eh_in_progress(hba);
 
 out:
+	spin_unlock_irqrestore(hba->host->host_lock, flags);
 	scsi_unblock_requests(hba->host);
 	ufshcd_release(hba);
 	pm_runtime_put_sync(hba->dev);
@@ -3896,15 +3962,18 @@ static void ufshcd_check_errors(struct ufs_hba *hba)
 	}
 
 	if (queue_eh_work) {
+		/*
+		 * update the transfer error masks to sticky bits, let's do this
+		 * irrespective of current ufshcd_state.
+		 */
+		hba->saved_err |= hba->errors;
+		hba->saved_uic_err |= hba->uic_error;
+
 		/* handle fatal errors only when link is functional */
 		if (hba->ufshcd_state == UFSHCD_STATE_OPERATIONAL) {
 			/* block commands from scsi mid-layer */
 			scsi_block_requests(hba->host);
 
-			/* transfer error masks to sticky bits */
-			hba->saved_err |= hba->errors;
-			hba->saved_uic_err |= hba->uic_error;
-
 			hba->ufshcd_state = UFSHCD_STATE_ERROR;
 			schedule_work(&hba->eh_work);
 		}