1 files changed, 54 insertions, 15 deletions

diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 0ddaf43d68c6..6728328f3bea 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -3790,21 +3790,45 @@ int sata_link_debounce(struct ata_link *link, const unsigned long *params,
 int sata_link_resume(struct ata_link *link, const unsigned long *params,
 		     unsigned long deadline)
 {
+	int tries = ATA_LINK_RESUME_TRIES;
 	u32 scontrol, serror;
 	int rc;
 
 	if ((rc = sata_scr_read(link, SCR_CONTROL, &scontrol)))
 		return rc;
 
-	scontrol = (scontrol & 0x0f0) | 0x300;
+	/*
+	 * Writes to SControl sometimes get ignored under certain
+	 * controllers (ata_piix SIDPR).  Make sure DET actually is
+	 * cleared.
+	 */
+	do {
+		scontrol = (scontrol & 0x0f0) | 0x300;
+		if ((rc = sata_scr_write(link, SCR_CONTROL, scontrol)))
+			return rc;
+		/*
+		 * Some PHYs react badly if SStatus is pounded
+		 * immediately after resuming.  Delay 200ms before
+		 * debouncing.
+		 */
+		msleep(200);
 
-	if ((rc = sata_scr_write(link, SCR_CONTROL, scontrol)))
-		return rc;
+		/* is SControl restored correctly? */
+		if ((rc = sata_scr_read(link, SCR_CONTROL, &scontrol)))
+			return rc;
+	} while ((scontrol & 0xf0f) != 0x300 && --tries);
 
-	/* Some PHYs react badly if SStatus is pounded immediately
-	 * after resuming.  Delay 200ms before debouncing.
-	 */
-	msleep(200);
+	if ((scontrol & 0xf0f) != 0x300) {
+		ata_link_printk(link, KERN_ERR,
+				"failed to resume link (SControl %X)\n",
+				scontrol);
+		return 0;
+	}
+
+	if (tries < ATA_LINK_RESUME_TRIES)
+		ata_link_printk(link, KERN_WARNING,
+				"link resume succeeded after %d retries\n",
+				ATA_LINK_RESUME_TRIES - tries);
 
 	if ((rc = sata_link_debounce(link, params, deadline)))
 		return rc;
@@ -4919,10 +4943,11 @@ struct ata_queued_cmd *ata_qc_new_init(struct ata_device *dev)
  */
 void ata_qc_free(struct ata_queued_cmd *qc)
 {
-	struct ata_port *ap = qc->ap;
+	struct ata_port *ap;
 	unsigned int tag;
 
 	WARN_ON_ONCE(qc == NULL); /* ata_qc_from_tag _might_ return NULL */
+	ap = qc->ap;
 
 	qc->flags = 0;
 	tag = qc->tag;
@@ -4934,11 +4959,13 @@ void ata_qc_free(struct ata_queued_cmd *qc)
 
 void __ata_qc_complete(struct ata_queued_cmd *qc)
 {
-	struct ata_port *ap = qc->ap;
-	struct ata_link *link = qc->dev->link;
+	struct ata_port *ap;
+	struct ata_link *link;
 
 	WARN_ON_ONCE(qc == NULL); /* ata_qc_from_tag _might_ return NULL */
 	WARN_ON_ONCE(!(qc->flags & ATA_QCFLAG_ACTIVE));
+	ap = qc->ap;
+	link = qc->dev->link;
 
 	if (likely(qc->flags & ATA_QCFLAG_DMAMAP))
 		ata_sg_clean(qc);
@@ -5028,12 +5055,14 @@ void ata_qc_complete(struct ata_queued_cmd *qc)
 			qc->flags |= ATA_QCFLAG_FAILED;
 
 		if (unlikely(qc->flags & ATA_QCFLAG_FAILED)) {
-			if (!ata_tag_internal(qc->tag)) {
-				/* always fill result TF for failed qc */
-				fill_result_tf(qc);
+			/* always fill result TF for failed qc */
+			fill_result_tf(qc);
+
+			if (!ata_tag_internal(qc->tag))
 				ata_qc_schedule_eh(qc);
-				return;
-			}
+			else
+				__ata_qc_complete(qc);
+			return;
 		}
 
 		WARN_ON_ONCE(ap->pflags & ATA_PFLAG_FROZEN);
@@ -5591,6 +5620,9 @@ void ata_link_init(struct ata_port *ap, struct ata_link *link, int pmp)
 
 		dev->link = link;
 		dev->devno = dev - link->device;
+#ifdef CONFIG_ATA_ACPI
+		dev->gtf_filter = ata_acpi_gtf_filter;
+#endif
 		ata_dev_init(dev);
 	}
 }
@@ -6608,6 +6640,13 @@ static int __init ata_init(void)
 {
 	ata_parse_force_param();
 
+	/*
+	 * FIXME: In UP case, there is only one workqueue thread and if you
+	 * have more than one PIO device, latency is bloody awful, with
+	 * occasional multi-second "hiccups" as one PIO device waits for
+	 * another.  It's an ugly wart that users DO occasionally complain
+	 * about; luckily most users have at most one PIO polled device.
+	 */
 	ata_wq = create_workqueue("ata");
 	if (!ata_wq)
 		goto free_force_tbl;