3 files changed, 53 insertions, 2 deletions

diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 86c10cc751e9..124b6f111cc3 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -5797,6 +5797,22 @@ static void fill_result_tf(struct ata_queued_cmd *qc)
         ap->ops->tf_read(ap, &qc->result_tf);
 }
 
+static void ata_verify_xfer(struct ata_queued_cmd *qc)
+{
+        struct ata_device *dev = qc->dev;
+
+        if (ata_tag_internal(qc->tag))
+                return;
+
+        if (ata_is_nodata(qc->tf.protocol))
+                return;
+
+        if ((dev->mwdma_mask || dev->udma_mask) && ata_is_pio(qc->tf.protocol))
+                return;
+
+        dev->flags &= ~ATA_DFLAG_DUBIOUS_XFER;
+}
+
 /**
  *      ata_qc_complete - Complete an active ATA command
  *      @qc: Command to complete
@@ -5868,6 +5884,9 @@ void ata_qc_complete(struct ata_queued_cmd *qc)
                         break;
                 }
 
+                if (unlikely(dev->flags & ATA_DFLAG_DUBIOUS_XFER))
+                        ata_verify_xfer(qc);
+
                 __ata_qc_complete(qc);
         } else {
                 if (qc->flags & ATA_QCFLAG_EH_SCHEDULED)
diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c
index 7d766ada7a5d..359a5ace8473 100644
--- a/drivers/ata/libata-eh.c
+++ b/drivers/ata/libata-eh.c
@@ -456,9 +456,20 @@ void ata_scsi_error(struct Scsi_Host *host)
                 spin_lock_irqsave(ap->lock, flags);
 
                 __ata_port_for_each_link(link, ap) {
+                        struct ata_eh_context *ehc = &link->eh_context;
+                        struct ata_device *dev;
+
                         memset(&link->eh_context, 0, sizeof(link->eh_context));
                         link->eh_context.i = link->eh_info;
                         memset(&link->eh_info, 0, sizeof(link->eh_info));
+
+                        ata_link_for_each_dev(dev, link) {
+                                int devno = dev->devno;
+
+                                ehc->saved_xfer_mode[devno] = dev->xfer_mode;
+                                if (ata_ncq_enabled(dev))
+                                        ehc->saved_ncq_enabled |= 1 << devno;
+                        }
                 }
 
                 ap->pflags |= ATA_PFLAG_EH_IN_PROGRESS;
@@ -2376,11 +2387,27 @@ static int ata_eh_revalidate_and_attach(struct ata_link *link,
 int ata_set_mode(struct ata_link *link, struct ata_device **r_failed_dev)
 {
         struct ata_port *ap = link->ap;
+        struct ata_device *dev;
+        int rc;
 
         /* has private set_mode? */
         if (ap->ops->set_mode)
-                return ap->ops->set_mode(link, r_failed_dev);
-        return ata_do_set_mode(link, r_failed_dev);
+                rc = ap->ops->set_mode(link, r_failed_dev);
+        else
+                rc = ata_do_set_mode(link, r_failed_dev);
+
+        /* if transfer mode has changed, set DUBIOUS_XFER on device */
+        ata_link_for_each_dev(dev, link) {
+                struct ata_eh_context *ehc = &link->eh_context;
+                u8 saved_xfer_mode = ehc->saved_xfer_mode[dev->devno];
+                u8 saved_ncq = !!(ehc->saved_ncq_enabled & (1 << dev->devno));
+
+                if (dev->xfer_mode != saved_xfer_mode ||
+                    ata_ncq_enabled(dev) != saved_ncq)
+                        dev->flags |= ATA_DFLAG_DUBIOUS_XFER;
+        }
+
+        return rc;
 }
 
 static int ata_link_nr_enabled(struct ata_link *link)
@@ -2441,6 +2468,8 @@ static int ata_eh_schedule_probe(struct ata_device *dev)
         ata_dev_init(dev);
         ehc->did_probe_mask |= (1 << dev->devno);
         ehc->i.action |= ATA_EH_SOFTRESET;
+        ehc->saved_xfer_mode[dev->devno] = 0;
+        ehc->saved_ncq_enabled &= ~(1 << dev->devno);
 
         return 1;
 }
diff --git a/include/linux/libata.h b/include/linux/libata.h
index 74f1255e2524..131fb6625e14 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -143,6 +143,7 @@ enum {
         ATA_DFLAG_NCQ_OFF       = (1 << 13), /* device limited to non-NCQ mode */
         ATA_DFLAG_SPUNDOWN      = (1 << 14), /* XXX: for spindown_compat */
         ATA_DFLAG_SLEEPING      = (1 << 15), /* device is sleeping */
+        ATA_DFLAG_DUBIOUS_XFER  = (1 << 16), /* data transfer not verified */
         ATA_DFLAG_INIT_MASK     = (1 << 24) - 1,
 
         ATA_DFLAG_DETACH        = (1 << 24),
@@ -560,6 +561,8 @@ struct ata_eh_context {
         int                     tries[ATA_MAX_DEVICES];
         unsigned int            classes[ATA_MAX_DEVICES];
         unsigned int            did_probe_mask;
+        unsigned int            saved_ncq_enabled;
+        u8                      saved_xfer_mode[ATA_MAX_DEVICES];
 };
 
 struct ata_acpi_drive