From: Tomas Henzl <thenzl@redhat.com>
Date: Tue, 17 Aug 2010 15:03:43 -0400
Subject: [scsi] mptsas: enable TLR for SSP TAPE drives
Message-id: <20100817150342.6769.21692.sendpatchset@localhost.localdomain>
Patchwork-id: 27663
O-Subject: [RHEL5.6 PATCH5/5] mptsas: Enable TLR for SSP TAPE drives
Bugzilla: 599420
RH-Acked-by: Stanislaw Gruszka <sgruszka@redhat.com>

If TLR is supported for end device, MPT2SAS driver will enable the TLR
bit in the SCSI_IO for every request. If there is a response with
MPI2_SCSITASKMGMT_RSP_INVALID_FRAME, the driver will turn off the TLR
logic. For RAID volume sas_is_tlr_enabled call will hit BUG at
scsi_transport_sas.c:163, since raid volume is not visible to sas transport layer.
Now Added check to make sure arg pass in sas_is_tlr_enabled() is not a volume.

http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=84f0b04a0e3b279a0b0a851b93eb403a626ca4b8
http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=3ed215259f2d8cd937abc833dc76e309173aaa52
Signed-off-by: Jarod Wilson <jarod@redhat.com>

diff --git a/drivers/scsi/mpt2sas/mpt2sas_scsih.c b/drivers/scsi/mpt2sas/mpt2sas_scsih.c
index 6168d32..dd451c0 100644
--- a/drivers/scsi/mpt2sas/mpt2sas_scsih.c
+++ b/drivers/scsi/mpt2sas/mpt2sas_scsih.c
@@ -1387,6 +1387,18 @@ _scsih_display_sata_capabilities(struct MPT2SAS_ADAPTER *ioc,
 }
 
 /**
+ * _scsih_is_raid - return boolean indicating device is raid volume
+ * @dev the device struct object
+ */
+static int
+_scsih_is_raid(struct device *dev)
+{
+	struct scsi_device *sdev = to_scsi_device(dev);
+
+	return (sdev->channel == RAID_CHANNEL) ? 1 : 0;
+}
+
+/**
  * _scsih_get_volume_capabilities - volume capabilities
  * @ioc: per adapter object
  * @sas_device: the raid_device object
@@ -1447,6 +1459,32 @@ _scsih_get_volume_capabilities(struct MPT2SAS_ADAPTER *ioc,
 }
 
 /**
+ * _scsih_enable_tlr - setting TLR flags
+ * @ioc: per adapter object
+ * @sdev: scsi device struct
+ *
+ * Enabling Transaction Layer Retries for tape devices when
+ * vpd page 0x90 is present
+ *
+ */
+static void
+_scsih_enable_tlr(struct MPT2SAS_ADAPTER *ioc, struct scsi_device *sdev)
+{
+	/* only for TAPE */
+	if (sdev->type != TYPE_TAPE)
+		return;
+
+	if (!(ioc->facts.IOCCapabilities & MPI2_IOCFACTS_CAPABILITY_TLR))
+		return;
+
+	sas_enable_tlr(sdev);
+	sdev_printk(KERN_INFO, sdev, "TLR %s\n",
+	    sas_is_tlr_enabled(sdev) ? "Enabled" : "Disabled");
+	return;
+
+}
+
+/**
  * _scsih_slave_configure - device configure routine.
  * @sdev: scsi device struct
  *
@@ -1589,8 +1627,10 @@ _scsih_slave_configure(struct scsi_device *sdev)
 
 	_scsih_change_queue_depth(sdev, qdepth);
 
-	if (ssp_target)
+	if (ssp_target) {
 		sas_read_port_mode_page(sdev);
+		_scsih_enable_tlr(ioc, sdev);
+    }
 
 #if defined(EEDP_SUPPORT)
 	if (ssp_target && (!(sas_target_priv_data->flags &
@@ -2644,8 +2684,9 @@ _scsih_qcmd(struct scsi_cmnd *scmd, void (*done)(struct scsi_cmnd *))
 
 	} else
 		mpi_control |= MPI2_SCSIIO_CONTROL_SIMPLEQ;
-
-	if ((sas_device_priv_data->flags & MPT_DEVICE_TLR_ON))
+	/* Make sure Device is not raid volume */
+	if (!_scsih_is_raid(&scmd->device->sdev_gendev) &&
+	    	sas_is_tlr_enabled(scmd->device))
 		mpi_control |= MPI2_SCSIIO_CONTROL_TLR_ON;
 
 	smid = mpt2sas_base_get_smid(ioc, ioc->scsi_io_cb_idx);
@@ -3031,15 +3072,17 @@ _scsih_io_done(struct MPT2SAS_ADAPTER *ioc, u16 smid, u8 VF_ID, u32 reply)
 	}
 
 	/* turning off TLR */
+	scsi_state = mpi_reply->SCSIState;
+	if (scsi_state & MPI2_SCSI_STATE_RESPONSE_INFO_VALID)
+		response_code =
+			le32_to_cpu(mpi_reply->ResponseInfo) & 0xFF;
 	if (!sas_device_priv_data->tlr_snoop_check) {
 		sas_device_priv_data->tlr_snoop_check++;
-		if (sas_device_priv_data->flags & MPT_DEVICE_TLR_ON) {
-			response_code = (le32_to_cpu(mpi_reply->ResponseInfo)
-			    >> 24);
-			if (response_code ==
-			    MPI2_SCSITASKMGMT_RSP_INVALID_FRAME)
-				sas_device_priv_data->flags &=
-				    ~MPT_DEVICE_TLR_ON;
+	if (!_scsih_is_raid(&scmd->device->sdev_gendev) &&
+		sas_is_tlr_enabled(scmd->device) &&
+		    response_code == MPI2_SCSITASKMGMT_RSP_INVALID_FRAME) {
+			sas_disable_tlr(scmd->device);
+			sdev_printk(KERN_INFO, scmd->device, "TLR disabled\n");
 		}
 	}
 
@@ -3051,7 +3094,6 @@ _scsih_io_done(struct MPT2SAS_ADAPTER *ioc, u16 smid, u8 VF_ID, u32 reply)
 	else
 		log_info = 0;
 	ioc_status &= MPI2_IOCSTATUS_MASK;
-	scsi_state = mpi_reply->SCSIState;
 	scsi_status = mpi_reply->SCSIStatus;
 
 	if (ioc_status == MPI2_IOCSTATUS_SCSI_DATA_UNDERRUN && xfer_cnt == 0 &&