diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index bf12f68..1db6eb0 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -2730,6 +2730,11 @@ int ata_down_xfermask_limit(struct ata_device *dev, unsigned int sel)
 		udma_mask = 0;
 		break;
 
+	case ATA_DNXFER_ANY:
+		highbit = fls(xfer_mask) - 1;
+		xfer_mask &= ~(1 << highbit);
+		break;
+
 	default:
 		BUG();
 	}
@@ -2773,6 +2778,12 @@ static int ata_dev_set_mode(struct ata_device *dev)
 	if (dev->xfer_shift == ATA_SHIFT_PIO && ata_id_is_cfa(dev->id))
         	err_mask &= ~AC_ERR_DEV;
 
+	if (err_mask == AC_ERR_DEV) {
+		ata_dev_printk(dev, KERN_WARNING, "device rejected "
+			       "transfer mode, lowering speed\n");
+		return -EAGAIN;
+	}
+
 	if (err_mask) {
 		ata_dev_printk(dev, KERN_ERR, "failed to set xfermode "
 			       "(err_mask=0x%x)\n", err_mask);
@@ -2912,10 +2923,24 @@ int ata_do_set_mode(struct ata_port *ap, struct ata_device **r_failed_dev)
  */
 int ata_set_mode(struct ata_port *ap, struct ata_device **r_failed_dev)
 {
+	int rc;
+
+ retry:
 	/* has private set_mode? */
 	if (ap->ops->set_mode)
-		return ap->ops->set_mode(ap, r_failed_dev);
-	return ata_do_set_mode(ap, r_failed_dev);
+		rc = ap->ops->set_mode(ap, r_failed_dev);
+	else
+		rc = ata_do_set_mode(ap, r_failed_dev);
+
+	/* lower speed and retry if driver or controller vetoed the mode */
+	if (rc == -EAGAIN) {
+		if (!(ap->pflags & ATA_PFLAG_FROZEN) &&
+		    !ata_down_xfermask_limit(*r_failed_dev, ATA_DNXFER_ANY))
+			goto retry;
+		rc = -EIO;
+	}
+
+	return rc;
 }
 
 /**
diff --git a/drivers/ata/libata.h b/drivers/ata/libata.h
index ba17fc5..ece1ecf 100644
--- a/drivers/ata/libata.h
+++ b/drivers/ata/libata.h
@@ -48,6 +48,7 @@ enum {
 	ATA_DNXFER_40C		= 2,	/* apply 40c cable limit */
 	ATA_DNXFER_FORCE_PIO	= 3,	/* force PIO */
 	ATA_DNXFER_FORCE_PIO0	= 4,	/* force PIO0 */
+	ATA_DNXFER_ANY		= 5,	/* speed down any */
 
 	ATA_DNXFER_QUIET	= (1 << 31),
 };