---

yaml
---
r: 29301
b: refs/heads/master
c: 2ab7db1
h: refs/heads/master
i:
  29299: a018ccb
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: dc2b3515868a254b3d653d77844bff93c5d4c095
+refs/heads/master: 2ab7db1ff1d64a2ba389d0692d532f42a15f1f72

trunk/drivers/scsi/libata-core.c

@@ -980,15 +980,39 @@ unsigned ata_exec_internal(struct ata_device *dev,
 	struct ata_port *ap = dev->ap;
 	u8 command = tf->command;
 	struct ata_queued_cmd *qc;
+	unsigned int tag, preempted_tag;
 	DECLARE_COMPLETION(wait);
 	unsigned long flags;
 	unsigned int err_mask;
 
 	spin_lock_irqsave(&ap->host_set->lock, flags);
 
-	qc = ata_qc_new_init(dev);
-	BUG_ON(qc == NULL);
+	/* initialize internal qc */
 
+	/* XXX: Tag 0 is used for drivers with legacy EH as some
+	 * drivers choke if any other tag is given.  This breaks
+	 * ata_tag_internal() test for those drivers.  Don't use new
+	 * EH stuff without converting to it.
+	 */
+	if (ap->ops->error_handler)
+		tag = ATA_TAG_INTERNAL;
+	else
+		tag = 0;
+
+	if (test_and_set_bit(tag, &ap->qactive))
+		BUG();
+	qc = ata_qc_from_tag(ap, tag);
+
+	qc->tag = tag;
+	qc->scsicmd = NULL;
+	qc->ap = ap;
+	qc->dev = dev;
+	ata_qc_reinit(qc);
+
+	preempted_tag = ap->active_tag;
+	ap->active_tag = ATA_TAG_POISON;
+
+	/* prepare & issue qc */
 	qc->tf = *tf;
 	if (cdb)
 		memcpy(qc->cdb, cdb, ATAPI_CDB_LEN);
@@ -1035,6 +1059,7 @@ unsigned ata_exec_internal(struct ata_device *dev,
 	err_mask = qc->err_mask;
 
 	ata_qc_free(qc);
+	ap->active_tag = preempted_tag;
 
 	/* XXX - Some LLDDs (sata_mv) disable port on command failure.
 	 * Until those drivers are fixed, we detect the condition
@@ -4014,7 +4039,8 @@ static struct ata_queued_cmd *ata_qc_new(struct ata_port *ap)
 	struct ata_queued_cmd *qc = NULL;
 	unsigned int i;
 
-	for (i = 0; i < ATA_MAX_QUEUE; i++)
+	/* the last tag is reserved for internal command. */
+	for (i = 0; i < ATA_MAX_QUEUE - 1; i++)
 		if (!test_and_set_bit(i, &ap->qactive)) {
 			qc = ata_qc_from_tag(ap, i);
 			break;

trunk/include/linux/libata.h

@@ -108,7 +108,9 @@ enum {
 	LIBATA_MAX_PRD		= ATA_MAX_PRD / 2,
 	ATA_MAX_PORTS		= 8,
 	ATA_DEF_QUEUE		= 1,
-	ATA_MAX_QUEUE		= 1,
+	/* tag ATA_MAX_QUEUE - 1 is reserved for internal commands */
+	ATA_MAX_QUEUE		= 2,
+	ATA_TAG_INTERNAL	= ATA_MAX_QUEUE - 1,
 	ATA_MAX_SECTORS		= 200,	/* FIXME */
 	ATA_MAX_BUS		= 2,
 	ATA_DEF_BUSY_WAIT	= 10000,
@@ -717,6 +719,11 @@ static inline unsigned int ata_tag_valid(unsigned int tag)
 	return (tag < ATA_MAX_QUEUE) ? 1 : 0;
 }
 
+static inline unsigned int ata_tag_internal(unsigned int tag)
+{
+	return tag == ATA_MAX_QUEUE - 1;
+}
+
 static inline unsigned int ata_class_enabled(unsigned int class)
 {
 	return class == ATA_DEV_ATA || class == ATA_DEV_ATAPI;