Merge branch 'for-4.0-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/libata

Pull libata fix from Tejun Heo:
 "One patch to fix a regression from the recent switch to blk-mq tag
  allocation which can cause oops on SAS-attached SATA drives"

* 'for-4.0-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/libata:
  ata: Add a new flag to destinguish sas controller

drivers/ata/libata-core.c

@@ -4737,7 +4737,7 @@ struct ata_queued_cmd *ata_qc_new_init(struct ata_device *dev, int tag)
 		return NULL;
 
 	/* libsas case */
-	if (!ap->scsi_host) {
+	if (ap->flags & ATA_FLAG_SAS_HOST) {
 		tag = ata_sas_allocate_tag(ap);
 		if (tag < 0)
 			return NULL;
@@ -4776,7 +4776,7 @@ void ata_qc_free(struct ata_queued_cmd *qc)
 	tag = qc->tag;
 	if (likely(ata_tag_valid(tag))) {
 		qc->tag = ATA_TAG_POISON;
-		if (!ap->scsi_host)
+		if (ap->flags & ATA_FLAG_SAS_HOST)
 			ata_sas_free_tag(tag, ap);
 	}
 }

drivers/scsi/ipr.c

@@ -6815,7 +6815,8 @@ static struct ata_port_operations ipr_sata_ops = {
 };
 
 static struct ata_port_info sata_port_info = {
-	.flags		= ATA_FLAG_SATA | ATA_FLAG_PIO_DMA,
+	.flags		= ATA_FLAG_SATA | ATA_FLAG_PIO_DMA |
+			  ATA_FLAG_SAS_HOST,
 	.pio_mask	= ATA_PIO4_ONLY,
 	.mwdma_mask	= ATA_MWDMA2,
 	.udma_mask	= ATA_UDMA6,

drivers/scsi/libsas/sas_ata.c

@@ -547,7 +547,8 @@ static struct ata_port_operations sas_sata_ops = {
 };
 
 static struct ata_port_info sata_port_info = {
-	.flags = ATA_FLAG_SATA | ATA_FLAG_PIO_DMA | ATA_FLAG_NCQ,
+	.flags = ATA_FLAG_SATA | ATA_FLAG_PIO_DMA | ATA_FLAG_NCQ |
+		 ATA_FLAG_SAS_HOST,
 	.pio_mask = ATA_PIO4,
 	.mwdma_mask = ATA_MWDMA2,
 	.udma_mask = ATA_UDMA6,

include/linux/libata.h

@@ -232,6 +232,7 @@ enum {
 					      * led */
 	ATA_FLAG_NO_DIPM	= (1 << 23), /* host not happy with DIPM */
 	ATA_FLAG_LOWTAG		= (1 << 24), /* host wants lowest available tag */
+	ATA_FLAG_SAS_HOST	= (1 << 25), /* SAS host */
 
 	/* bits 24:31 of ap->flags are reserved for LLD specific flags */