diff mbox

[V7,6/6] scsi: ufs: Improve UFS fatal error handling

Message ID 1379589248-3317-7-git-send-email-sthumma@codeaurora.org (mailing list archive)
State Not Applicable, archived
Headers show

Commit Message

Sujit Reddy Thumma Sept. 19, 2013, 11:14 a.m. UTC
Error handling in UFS driver is broken and resets the host controller
for fatal errors without re-initialization. Correct the fatal error
handling sequence according to UFS Host Controller Interface (HCI)
v1.1 specification.

o Processed requests which are completed w/wo error are reported to
  SCSI layer and any pending commands that are not started are aborted
  in the controller and re-queued into scsi mid-layer queue.

o Upon determining fatal error condition the host controller may hang
  forever until a reset is applied. Block SCSI layer for sending new
  requests and apply reset in a separate error handling work.

o SCSI is informed about the expected Unit-Attention exception from the
  device for the immediate command after a reset so that the SCSI layer
  take necessary steps to establish communication with the device.

Signed-off-by: Sujit Reddy Thumma <sthumma@codeaurora.org>
Reviewed-by: Yaniv Gardi <ygardi@codeaurora.org>
Tested-by: Dolev Raviv <draviv@codeaurora.org>
---
 drivers/scsi/ufs/ufshcd.c | 229 ++++++++++++++++++++++++++++------------------
 drivers/scsi/ufs/ufshcd.h |  10 +-
 2 files changed, 149 insertions(+), 90 deletions(-)

Comments

Vinayak Holikatti Sept. 23, 2013, 12:17 p.m. UTC | #1
On Thu, Sep 19, 2013 at 4:44 PM, Sujit Reddy Thumma
<sthumma@codeaurora.org> wrote:
> Error handling in UFS driver is broken and resets the host controller
> for fatal errors without re-initialization. Correct the fatal error
> handling sequence according to UFS Host Controller Interface (HCI)
> v1.1 specification.
>
> o Processed requests which are completed w/wo error are reported to
>   SCSI layer and any pending commands that are not started are aborted
>   in the controller and re-queued into scsi mid-layer queue.
>
> o Upon determining fatal error condition the host controller may hang
>   forever until a reset is applied. Block SCSI layer for sending new
>   requests and apply reset in a separate error handling work.
>
> o SCSI is informed about the expected Unit-Attention exception from the
>   device for the immediate command after a reset so that the SCSI layer
>   take necessary steps to establish communication with the device.
>
> Signed-off-by: Sujit Reddy Thumma <sthumma@codeaurora.org>
> Reviewed-by: Yaniv Gardi <ygardi@codeaurora.org>
> Tested-by: Dolev Raviv <draviv@codeaurora.org>
> ---
>  drivers/scsi/ufs/ufshcd.c | 229 ++++++++++++++++++++++++++++------------------
>  drivers/scsi/ufs/ufshcd.h |  10 +-
>  2 files changed, 149 insertions(+), 90 deletions(-)
>
> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> index 5462310..0c28772 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -84,6 +84,14 @@ enum {
>         UFSHCD_EH_IN_PROGRESS = (1 << 0),
>  };
>
> +/* 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 */
> +};
> +
>  /* Interrupt configuration options */
>  enum {
>         UFSHCD_INT_DISABLE,
> @@ -100,6 +108,8 @@ enum {
>
>  static void ufshcd_tmc_handler(struct ufs_hba *hba);
>  static void ufshcd_async_scan(void *data, async_cookie_t cookie);
> +static int ufshcd_reset_and_restore(struct ufs_hba *hba);
> +static int ufshcd_clear_tm_cmd(struct ufs_hba *hba, int tag);
>
>  /*
>   * ufshcd_wait_for_register - wait for register value to change
> @@ -1735,9 +1745,6 @@ static int ufshcd_make_hba_operational(struct ufs_hba *hba)
>                 goto out;
>         }
>
> -       if (hba->ufshcd_state == UFSHCD_STATE_RESET)
> -               scsi_unblock_requests(hba->host);
> -
>  out:
>         return err;
>  }
> @@ -1863,66 +1870,6 @@ static int ufshcd_verify_dev_init(struct ufs_hba *hba)
>  }
>
>  /**
> - * ufshcd_do_reset - reset the host controller
> - * @hba: per adapter instance
> - *
> - * Returns SUCCESS/FAILED
> - */
> -static int ufshcd_do_reset(struct ufs_hba *hba)
> -{
> -       struct ufshcd_lrb *lrbp;
> -       unsigned long flags;
> -       int tag;
> -
> -       /* block commands from midlayer */
> -       scsi_block_requests(hba->host);
> -
> -       spin_lock_irqsave(hba->host->host_lock, flags);
> -       hba->ufshcd_state = UFSHCD_STATE_RESET;
> -
> -       /* send controller to reset state */
> -       ufshcd_hba_stop(hba);
> -       spin_unlock_irqrestore(hba->host->host_lock, flags);
> -
> -       /* abort outstanding commands */
> -       for (tag = 0; tag < hba->nutrs; tag++) {
> -               if (test_bit(tag, &hba->outstanding_reqs)) {
> -                       lrbp = &hba->lrb[tag];
> -                       if (lrbp->cmd) {
> -                               scsi_dma_unmap(lrbp->cmd);
> -                               lrbp->cmd->result = DID_RESET << 16;
> -                               lrbp->cmd->scsi_done(lrbp->cmd);
> -                               lrbp->cmd = NULL;
> -                               clear_bit_unlock(tag, &hba->lrb_in_use);
> -                       }
> -               }
> -       }
> -
> -       /* complete device management command */
> -       if (hba->dev_cmd.complete)
> -               complete(hba->dev_cmd.complete);
> -
> -       /* clear outstanding request/task bit maps */
> -       hba->outstanding_reqs = 0;
> -       hba->outstanding_tasks = 0;
> -
> -       /* Host controller enable */
> -       if (ufshcd_hba_enable(hba)) {
> -               dev_err(hba->dev,
> -                       "Reset: Controller initialization failed\n");
> -               return FAILED;
> -       }
> -
> -       if (ufshcd_link_startup(hba)) {
> -               dev_err(hba->dev,
> -                       "Reset: Link start-up failed\n");
> -               return FAILED;
> -       }
> -
> -       return SUCCESS;
> -}
> -
> -/**
>   * ufshcd_slave_alloc - handle initial SCSI device configurations
>   * @sdev: pointer to SCSI device
>   *
> @@ -1939,6 +1886,9 @@ static int ufshcd_slave_alloc(struct scsi_device *sdev)
>         sdev->use_10_for_ms = 1;
>         scsi_set_tag_type(sdev, MSG_SIMPLE_TAG);
>
> +       /* allow SCSI layer to restart the device in case of errors */
> +       sdev->allow_restart = 1;
> +
>         /*
>          * Inform SCSI Midlayer that the LUN queue depth is same as the
>          * controller queue depth. If a LUN queue depth is less than the
> @@ -2134,6 +2084,9 @@ ufshcd_transfer_rsp_status(struct ufs_hba *hba, struct ufshcd_lrb *lrbp)
>         case OCS_ABORTED:
>                 result |= DID_ABORT << 16;
>                 break;
> +       case OCS_INVALID_COMMAND_STATUS:
> +               result |= DID_REQUEUE << 16;
> +               break;
>         case OCS_INVALID_CMD_TABLE_ATTR:
>         case OCS_INVALID_PRDT_ATTR:
>         case OCS_MISMATCH_DATA_BUF_SIZE:
> @@ -2451,45 +2404,145 @@ out:
>  }
>
>  /**
> - * ufshcd_fatal_err_handler - handle fatal errors
> - * @hba: per adapter instance
> + * ufshcd_err_handler - handle UFS errors that require s/w attention
> + * @work: pointer to work structure
>   */
> -static void ufshcd_fatal_err_handler(struct work_struct *work)
> +static void ufshcd_err_handler(struct work_struct *work)
>  {
>         struct ufs_hba *hba;
> -       hba = container_of(work, struct ufs_hba, feh_workq);
> +       unsigned long flags;
> +       u32 err_xfer = 0;
> +       u32 err_tm = 0;
> +       int err = 0;
> +       int tag;
> +
> +       hba = container_of(work, struct ufs_hba, eh_work);
>
>         pm_runtime_get_sync(hba->dev);
> -       /* check if reset is already in progress */
> -       if (hba->ufshcd_state != UFSHCD_STATE_RESET)
> -               ufshcd_do_reset(hba);
> +
> +       spin_lock_irqsave(hba->host->host_lock, flags);
> +       if (hba->ufshcd_state == UFSHCD_STATE_RESET) {
> +               spin_unlock_irqrestore(hba->host->host_lock, flags);
> +               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);
> +
> +       /* Clear pending transfer requests */
> +       for_each_set_bit(tag, &hba->outstanding_reqs, hba->nutrs)
> +               if (ufshcd_clear_cmd(hba, tag))
> +                       err_xfer |= 1 << tag;
> +
> +       /* 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;
> +
> +       /* Complete the requests that are cleared by s/w */
> +       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);
> +
> +       /* 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))) {
> +               err = ufshcd_reset_and_restore(hba);
> +               if (err) {
> +                       dev_err(hba->dev, "%s: reset and restore failed\n",
> +                                       __func__);
> +                       hba->ufshcd_state = UFSHCD_STATE_ERROR;
> +               }
> +               /*
> +                * Inform scsi mid-layer that we did reset and allow to handle
> +                * Unit Attention properly.
> +                */
> +               scsi_report_bus_reset(hba->host, 0);
> +               hba->saved_err = 0;
> +               hba->saved_uic_err = 0;
> +       }
> +       ufshcd_clear_eh_in_progress(hba);
> +
> +out:
> +       scsi_unblock_requests(hba->host);
>         pm_runtime_put_sync(hba->dev);
>  }
>
>  /**
> - * ufshcd_err_handler - Check for fatal errors
> - * @work: pointer to a work queue structure
> + * ufshcd_update_uic_error - check and set fatal UIC error flags.
> + * @hba: per-adapter instance
>   */
> -static void ufshcd_err_handler(struct ufs_hba *hba)
> +static void ufshcd_update_uic_error(struct ufs_hba *hba)
>  {
>         u32 reg;
>
> +       /* PA_INIT_ERROR is fatal and needs UIC reset */
> +       reg = ufshcd_readl(hba, REG_UIC_ERROR_CODE_DATA_LINK_LAYER);
> +       if (reg & UIC_DATA_LINK_LAYER_ERROR_PA_INIT)
> +               hba->uic_error |= UFSHCD_UIC_DL_PA_INIT_ERROR;
> +
> +       /* UIC NL/TL/DME errors needs software retry */
> +       reg = ufshcd_readl(hba, REG_UIC_ERROR_CODE_NETWORK_LAYER);
> +       if (reg)
> +               hba->uic_error |= UFSHCD_UIC_NL_ERROR;
> +
> +       reg = ufshcd_readl(hba, REG_UIC_ERROR_CODE_TRANSPORT_LAYER);
> +       if (reg)
> +               hba->uic_error |= UFSHCD_UIC_TL_ERROR;
> +
> +       reg = ufshcd_readl(hba, REG_UIC_ERROR_CODE_DME);
> +       if (reg)
> +               hba->uic_error |= UFSHCD_UIC_DME_ERROR;
> +
> +       dev_dbg(hba->dev, "%s: UIC error flags = 0x%08x\n",
> +                       __func__, hba->uic_error);
> +}
> +
> +/**
> + * ufshcd_check_errors - Check for errors that need s/w attention
> + * @hba: per-adapter instance
> + */
> +static void ufshcd_check_errors(struct ufs_hba *hba)
> +{
> +       bool queue_eh_work = false;
> +
>         if (hba->errors & INT_FATAL_ERRORS)
> -               goto fatal_eh;
> +               queue_eh_work = true;
>
>         if (hba->errors & UIC_ERROR) {
> -               reg = ufshcd_readl(hba, REG_UIC_ERROR_CODE_DATA_LINK_LAYER);
> -               if (reg & UIC_DATA_LINK_LAYER_ERROR_PA_INIT)
> -                       goto fatal_eh;
> +               hba->uic_error = 0;
> +               ufshcd_update_uic_error(hba);
> +               if (hba->uic_error)
> +                       queue_eh_work = true;
>         }
> -       return;
> -fatal_eh:
> -       /* handle fatal errors only when link is functional */
> -       if (hba->ufshcd_state == UFSHCD_STATE_OPERATIONAL) {
> -               /* block commands at driver layer until error is handled */
> -               hba->ufshcd_state = UFSHCD_STATE_ERROR;
> -               schedule_work(&hba->feh_workq);
> +
> +       if (queue_eh_work) {
> +               /* 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);
> +               }
>         }
> +       /*
> +        * if (!queue_eh_work) -
> +        * Other errors are either non-fatal where host recovers
> +        * itself without s/w intervention or errors that will be
> +        * handled by the SCSI core layer.
> +        */
>  }
>
>  /**
> @@ -2514,7 +2567,7 @@ static void ufshcd_sl_intr(struct ufs_hba *hba, u32 intr_status)
>  {
>         hba->errors = UFSHCD_ERROR_MASK & intr_status;
>         if (hba->errors)
> -               ufshcd_err_handler(hba);
> +               ufshcd_check_errors(hba);
>
>         if (intr_status & UFSHCD_UIC_MASK)
>                 ufshcd_uic_cmd_compl(hba, intr_status);
> @@ -2889,12 +2942,12 @@ static int ufshcd_eh_host_reset_handler(struct scsi_cmnd *cmd)
>          */
>         do {
>                 spin_lock_irqsave(hba->host->host_lock, flags);
> -               if (!(work_pending(&hba->feh_workq) ||
> +               if (!(work_pending(&hba->eh_work) ||
>                                 hba->ufshcd_state == UFSHCD_STATE_RESET))
>                         break;
>                 spin_unlock_irqrestore(hba->host->host_lock, flags);
>                 dev_dbg(hba->dev, "%s: reset in progress\n", __func__);
> -               flush_work(&hba->feh_workq);
> +               flush_work(&hba->eh_work);
>         } while (1);
>
>         hba->ufshcd_state = UFSHCD_STATE_RESET;
> @@ -3130,7 +3183,7 @@ int ufshcd_init(struct device *dev, struct ufs_hba **hba_handle,
>         init_waitqueue_head(&hba->tm_tag_wq);
>
>         /* Initialize work queues */
> -       INIT_WORK(&hba->feh_workq, ufshcd_fatal_err_handler);
> +       INIT_WORK(&hba->eh_work, ufshcd_err_handler);
>         INIT_WORK(&hba->eeh_work, ufshcd_exception_event_handler);
>
>         /* Initialize UIC command mutex */
> diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
> index 48c7d9b..acf318e 100644
> --- a/drivers/scsi/ufs/ufshcd.h
> +++ b/drivers/scsi/ufs/ufshcd.h
> @@ -183,9 +183,12 @@ struct ufs_dev_cmd {
>   * @eh_flags: Error handling flags
>   * @intr_mask: Interrupt Mask Bits
>   * @ee_ctrl_mask: Exception event control mask
> - * @feh_workq: Work queue for fatal controller error handling
> + * @eh_work: Worker to handle UFS errors that require s/w attention
>   * @eeh_work: Worker to handle exception events
>   * @errors: HBA errors
> + * @uic_error: UFS interconnect layer error status
> + * @saved_err: sticky error mask
> + * @saved_uic_err: sticky UIC error mask
>   * @dev_cmd: ufs device management command information
>   * @auto_bkops_enabled: to track whether bkops is enabled in device
>   */
> @@ -233,11 +236,14 @@ struct ufs_hba {
>         u16 ee_ctrl_mask;
>
>         /* Work Queues */
> -       struct work_struct feh_workq;
> +       struct work_struct eh_work;
>         struct work_struct eeh_work;
>
>         /* HBA Errors */
>         u32 errors;
> +       u32 uic_error;
> +       u32 saved_err;
> +       u32 saved_uic_err;
>
>         /* Device management request data */
>         struct ufs_dev_cmd dev_cmd;

Acked-by: Vinayak Holikatti <vinholikatti@gmail.com>
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diff mbox

Patch

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 5462310..0c28772 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -84,6 +84,14 @@  enum {
 	UFSHCD_EH_IN_PROGRESS = (1 << 0),
 };
 
+/* 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 */
+};
+
 /* Interrupt configuration options */
 enum {
 	UFSHCD_INT_DISABLE,
@@ -100,6 +108,8 @@  enum {
 
 static void ufshcd_tmc_handler(struct ufs_hba *hba);
 static void ufshcd_async_scan(void *data, async_cookie_t cookie);
+static int ufshcd_reset_and_restore(struct ufs_hba *hba);
+static int ufshcd_clear_tm_cmd(struct ufs_hba *hba, int tag);
 
 /*
  * ufshcd_wait_for_register - wait for register value to change
@@ -1735,9 +1745,6 @@  static int ufshcd_make_hba_operational(struct ufs_hba *hba)
 		goto out;
 	}
 
-	if (hba->ufshcd_state == UFSHCD_STATE_RESET)
-		scsi_unblock_requests(hba->host);
-
 out:
 	return err;
 }
@@ -1863,66 +1870,6 @@  static int ufshcd_verify_dev_init(struct ufs_hba *hba)
 }
 
 /**
- * ufshcd_do_reset - reset the host controller
- * @hba: per adapter instance
- *
- * Returns SUCCESS/FAILED
- */
-static int ufshcd_do_reset(struct ufs_hba *hba)
-{
-	struct ufshcd_lrb *lrbp;
-	unsigned long flags;
-	int tag;
-
-	/* block commands from midlayer */
-	scsi_block_requests(hba->host);
-
-	spin_lock_irqsave(hba->host->host_lock, flags);
-	hba->ufshcd_state = UFSHCD_STATE_RESET;
-
-	/* send controller to reset state */
-	ufshcd_hba_stop(hba);
-	spin_unlock_irqrestore(hba->host->host_lock, flags);
-
-	/* abort outstanding commands */
-	for (tag = 0; tag < hba->nutrs; tag++) {
-		if (test_bit(tag, &hba->outstanding_reqs)) {
-			lrbp = &hba->lrb[tag];
-			if (lrbp->cmd) {
-				scsi_dma_unmap(lrbp->cmd);
-				lrbp->cmd->result = DID_RESET << 16;
-				lrbp->cmd->scsi_done(lrbp->cmd);
-				lrbp->cmd = NULL;
-				clear_bit_unlock(tag, &hba->lrb_in_use);
-			}
-		}
-	}
-
-	/* complete device management command */
-	if (hba->dev_cmd.complete)
-		complete(hba->dev_cmd.complete);
-
-	/* clear outstanding request/task bit maps */
-	hba->outstanding_reqs = 0;
-	hba->outstanding_tasks = 0;
-
-	/* Host controller enable */
-	if (ufshcd_hba_enable(hba)) {
-		dev_err(hba->dev,
-			"Reset: Controller initialization failed\n");
-		return FAILED;
-	}
-
-	if (ufshcd_link_startup(hba)) {
-		dev_err(hba->dev,
-			"Reset: Link start-up failed\n");
-		return FAILED;
-	}
-
-	return SUCCESS;
-}
-
-/**
  * ufshcd_slave_alloc - handle initial SCSI device configurations
  * @sdev: pointer to SCSI device
  *
@@ -1939,6 +1886,9 @@  static int ufshcd_slave_alloc(struct scsi_device *sdev)
 	sdev->use_10_for_ms = 1;
 	scsi_set_tag_type(sdev, MSG_SIMPLE_TAG);
 
+	/* allow SCSI layer to restart the device in case of errors */
+	sdev->allow_restart = 1;
+
 	/*
 	 * Inform SCSI Midlayer that the LUN queue depth is same as the
 	 * controller queue depth. If a LUN queue depth is less than the
@@ -2134,6 +2084,9 @@  ufshcd_transfer_rsp_status(struct ufs_hba *hba, struct ufshcd_lrb *lrbp)
 	case OCS_ABORTED:
 		result |= DID_ABORT << 16;
 		break;
+	case OCS_INVALID_COMMAND_STATUS:
+		result |= DID_REQUEUE << 16;
+		break;
 	case OCS_INVALID_CMD_TABLE_ATTR:
 	case OCS_INVALID_PRDT_ATTR:
 	case OCS_MISMATCH_DATA_BUF_SIZE:
@@ -2451,45 +2404,145 @@  out:
 }
 
 /**
- * ufshcd_fatal_err_handler - handle fatal errors
- * @hba: per adapter instance
+ * ufshcd_err_handler - handle UFS errors that require s/w attention
+ * @work: pointer to work structure
  */
-static void ufshcd_fatal_err_handler(struct work_struct *work)
+static void ufshcd_err_handler(struct work_struct *work)
 {
 	struct ufs_hba *hba;
-	hba = container_of(work, struct ufs_hba, feh_workq);
+	unsigned long flags;
+	u32 err_xfer = 0;
+	u32 err_tm = 0;
+	int err = 0;
+	int tag;
+
+	hba = container_of(work, struct ufs_hba, eh_work);
 
 	pm_runtime_get_sync(hba->dev);
-	/* check if reset is already in progress */
-	if (hba->ufshcd_state != UFSHCD_STATE_RESET)
-		ufshcd_do_reset(hba);
+
+	spin_lock_irqsave(hba->host->host_lock, flags);
+	if (hba->ufshcd_state == UFSHCD_STATE_RESET) {
+		spin_unlock_irqrestore(hba->host->host_lock, flags);
+		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);
+
+	/* Clear pending transfer requests */
+	for_each_set_bit(tag, &hba->outstanding_reqs, hba->nutrs)
+		if (ufshcd_clear_cmd(hba, tag))
+			err_xfer |= 1 << tag;
+
+	/* 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;
+
+	/* Complete the requests that are cleared by s/w */
+	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);
+
+	/* 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))) {
+		err = ufshcd_reset_and_restore(hba);
+		if (err) {
+			dev_err(hba->dev, "%s: reset and restore failed\n",
+					__func__);
+			hba->ufshcd_state = UFSHCD_STATE_ERROR;
+		}
+		/*
+		 * Inform scsi mid-layer that we did reset and allow to handle
+		 * Unit Attention properly.
+		 */
+		scsi_report_bus_reset(hba->host, 0);
+		hba->saved_err = 0;
+		hba->saved_uic_err = 0;
+	}
+	ufshcd_clear_eh_in_progress(hba);
+
+out:
+	scsi_unblock_requests(hba->host);
 	pm_runtime_put_sync(hba->dev);
 }
 
 /**
- * ufshcd_err_handler - Check for fatal errors
- * @work: pointer to a work queue structure
+ * ufshcd_update_uic_error - check and set fatal UIC error flags.
+ * @hba: per-adapter instance
  */
-static void ufshcd_err_handler(struct ufs_hba *hba)
+static void ufshcd_update_uic_error(struct ufs_hba *hba)
 {
 	u32 reg;
 
+	/* PA_INIT_ERROR is fatal and needs UIC reset */
+	reg = ufshcd_readl(hba, REG_UIC_ERROR_CODE_DATA_LINK_LAYER);
+	if (reg & UIC_DATA_LINK_LAYER_ERROR_PA_INIT)
+		hba->uic_error |= UFSHCD_UIC_DL_PA_INIT_ERROR;
+
+	/* UIC NL/TL/DME errors needs software retry */
+	reg = ufshcd_readl(hba, REG_UIC_ERROR_CODE_NETWORK_LAYER);
+	if (reg)
+		hba->uic_error |= UFSHCD_UIC_NL_ERROR;
+
+	reg = ufshcd_readl(hba, REG_UIC_ERROR_CODE_TRANSPORT_LAYER);
+	if (reg)
+		hba->uic_error |= UFSHCD_UIC_TL_ERROR;
+
+	reg = ufshcd_readl(hba, REG_UIC_ERROR_CODE_DME);
+	if (reg)
+		hba->uic_error |= UFSHCD_UIC_DME_ERROR;
+
+	dev_dbg(hba->dev, "%s: UIC error flags = 0x%08x\n",
+			__func__, hba->uic_error);
+}
+
+/**
+ * ufshcd_check_errors - Check for errors that need s/w attention
+ * @hba: per-adapter instance
+ */
+static void ufshcd_check_errors(struct ufs_hba *hba)
+{
+	bool queue_eh_work = false;
+
 	if (hba->errors & INT_FATAL_ERRORS)
-		goto fatal_eh;
+		queue_eh_work = true;
 
 	if (hba->errors & UIC_ERROR) {
-		reg = ufshcd_readl(hba, REG_UIC_ERROR_CODE_DATA_LINK_LAYER);
-		if (reg & UIC_DATA_LINK_LAYER_ERROR_PA_INIT)
-			goto fatal_eh;
+		hba->uic_error = 0;
+		ufshcd_update_uic_error(hba);
+		if (hba->uic_error)
+			queue_eh_work = true;
 	}
-	return;
-fatal_eh:
-	/* handle fatal errors only when link is functional */
-	if (hba->ufshcd_state == UFSHCD_STATE_OPERATIONAL) {
-		/* block commands at driver layer until error is handled */
-		hba->ufshcd_state = UFSHCD_STATE_ERROR;
-		schedule_work(&hba->feh_workq);
+
+	if (queue_eh_work) {
+		/* 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);
+		}
 	}
+	/*
+	 * if (!queue_eh_work) -
+	 * Other errors are either non-fatal where host recovers
+	 * itself without s/w intervention or errors that will be
+	 * handled by the SCSI core layer.
+	 */
 }
 
 /**
@@ -2514,7 +2567,7 @@  static void ufshcd_sl_intr(struct ufs_hba *hba, u32 intr_status)
 {
 	hba->errors = UFSHCD_ERROR_MASK & intr_status;
 	if (hba->errors)
-		ufshcd_err_handler(hba);
+		ufshcd_check_errors(hba);
 
 	if (intr_status & UFSHCD_UIC_MASK)
 		ufshcd_uic_cmd_compl(hba, intr_status);
@@ -2889,12 +2942,12 @@  static int ufshcd_eh_host_reset_handler(struct scsi_cmnd *cmd)
 	 */
 	do {
 		spin_lock_irqsave(hba->host->host_lock, flags);
-		if (!(work_pending(&hba->feh_workq) ||
+		if (!(work_pending(&hba->eh_work) ||
 				hba->ufshcd_state == UFSHCD_STATE_RESET))
 			break;
 		spin_unlock_irqrestore(hba->host->host_lock, flags);
 		dev_dbg(hba->dev, "%s: reset in progress\n", __func__);
-		flush_work(&hba->feh_workq);
+		flush_work(&hba->eh_work);
 	} while (1);
 
 	hba->ufshcd_state = UFSHCD_STATE_RESET;
@@ -3130,7 +3183,7 @@  int ufshcd_init(struct device *dev, struct ufs_hba **hba_handle,
 	init_waitqueue_head(&hba->tm_tag_wq);
 
 	/* Initialize work queues */
-	INIT_WORK(&hba->feh_workq, ufshcd_fatal_err_handler);
+	INIT_WORK(&hba->eh_work, ufshcd_err_handler);
 	INIT_WORK(&hba->eeh_work, ufshcd_exception_event_handler);
 
 	/* Initialize UIC command mutex */
diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
index 48c7d9b..acf318e 100644
--- a/drivers/scsi/ufs/ufshcd.h
+++ b/drivers/scsi/ufs/ufshcd.h
@@ -183,9 +183,12 @@  struct ufs_dev_cmd {
  * @eh_flags: Error handling flags
  * @intr_mask: Interrupt Mask Bits
  * @ee_ctrl_mask: Exception event control mask
- * @feh_workq: Work queue for fatal controller error handling
+ * @eh_work: Worker to handle UFS errors that require s/w attention
  * @eeh_work: Worker to handle exception events
  * @errors: HBA errors
+ * @uic_error: UFS interconnect layer error status
+ * @saved_err: sticky error mask
+ * @saved_uic_err: sticky UIC error mask
  * @dev_cmd: ufs device management command information
  * @auto_bkops_enabled: to track whether bkops is enabled in device
  */
@@ -233,11 +236,14 @@  struct ufs_hba {
 	u16 ee_ctrl_mask;
 
 	/* Work Queues */
-	struct work_struct feh_workq;
+	struct work_struct eh_work;
 	struct work_struct eeh_work;
 
 	/* HBA Errors */
 	u32 errors;
+	u32 uic_error;
+	u32 saved_err;
+	u32 saved_uic_err;
 
 	/* Device management request data */
 	struct ufs_dev_cmd dev_cmd;