Re: [PATCH] libata: revert "libata: use blk taging" et al.

[Shaohua Li <shli@fb.com>]

On Thu, Mar 12, 2015 at 08:11:57AM -0400, Tejun Heo wrote:
> On Thu, Mar 12, 2015 at 06:14:24AM -0400, Dan Williams wrote:
> > > @@ -572,7 +572,6 @@ int sas_ata_init(struct domain_device *found_dev)
> > >
> > >         ap->private_data = found_dev;
> > >         ap->cbl = ATA_CBL_SATA;
> > > -       ap->scsi_host = shost;
> > >         rc = ata_sas_port_init(ap);
> > >         if (rc) {
> > >                 ata_sas_port_destroy(ap);
> > 
> > We need a scsi_host for error recovery, see:
> > 
> > ata_std_sched_eh()
> 
> IOW, let's just add a flag bit to identify SAS hosts.

Yep. Tony, can you please try below patch please?


ata: Add a new flag for sas controller

Add a new flag to destinguish sas controller. sas controller has its own tag
allocation, which doesn't directly match to ata tag. We use the new flag for
sas ata tag allocation.

Reported-by: Tony Battersby <tonyb@cybernetics.com>
Signed-off-by: Shaohua Li <shli@fb.com>

diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 4c35f08..ef150eb 100644
--- a/drivers/ata/libata-core.c
+++ b/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);
 	}
 }
diff --git a/drivers/scsi/ipr.c b/drivers/scsi/ipr.c
index 9219953..d9afc51 100644
--- a/drivers/scsi/ipr.c
+++ b/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,
diff --git a/drivers/scsi/libsas/sas_ata.c b/drivers/scsi/libsas/sas_ata.c
index 932d9cc..9c706d8 100644
--- a/drivers/scsi/libsas/sas_ata.c
+++ b/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,
diff --git a/include/linux/libata.h b/include/linux/libata.h
index fc03efa..6b08cc1 100644
--- a/include/linux/libata.h
+++ b/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 */