mpt3sas: Never block the Enclosure device

BugLink: http://bugs.launchpad.net/bugs/1512221

Never block the SEP device (i.e. Never invoke the
scsi_internal_device_block() API for SEP device) even for the delay not
responding events. Blocking the SEP device will create a deadlock while
adding any device to the OS.
Signed-off-by: Suganath prabu Subramani <suganath-prabu.subramani@avagotech.com>
Signed-off-by: Chaitra P B <chaitra.basappa@avagotech.com>
Reviewed-by: Tomas Henzl <thenzl@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
(cherry picked from commit b17d0b7ff0768070180e1021c0f32988445644d8)
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>

drivers/scsi/mpt3sas/mpt3sas_base.h

@@ -398,6 +398,7 @@ struct MPT3SAS_DEVICE {
 	u8	configured_lun;
 	u8	block;
 	u8	tlr_snoop_check;
+	u8	ignore_delay_remove;
 };
 
 #define MPT3_CMD_NOT_USED	0x8000	/* free */

drivers/scsi/mpt3sas/mpt3sas_scsih.c

@@ -1953,7 +1953,15 @@ scsih_slave_configure(struct scsi_device *sdev)
 	if (sas_device->device_info & MPI2_SAS_DEVICE_INFO_SSP_TARGET) {
 		qdepth = MPT3SAS_SAS_QUEUE_DEPTH;
 		ssp_target = 1;
-		ds = "SSP";
+		if (sas_device->device_info &
+				MPI2_SAS_DEVICE_INFO_SEP) {
+			sdev_printk(KERN_WARNING, sdev,
+			"set ignore_delay_remove for handle(0x%04x)\n",
+			sas_device_priv_data->sas_target->handle);
+			sas_device_priv_data->ignore_delay_remove = 1;
+			ds = "SES";
+		} else
+			ds = "SSP";
 	} else {
 		qdepth = MPT3SAS_SATA_QUEUE_DEPTH;
 		if (sas_device->device_info & MPI2_SAS_DEVICE_INFO_STP_TARGET)
@@ -2943,6 +2951,12 @@ _scsih_block_io_all_device(struct MPT3SAS_ADAPTER *ioc)
 			continue;
 		if (sas_device_priv_data->block)
 			continue;
+		if (sas_device_priv_data->ignore_delay_remove) {
+			sdev_printk(KERN_INFO, sdev,
+			"%s skip device_block for SES handle(0x%04x)\n",
+			__func__, sas_device_priv_data->sas_target->handle);
+			continue;
+		}
 		_scsih_internal_device_block(sdev, sas_device_priv_data);
 	}
 }
@@ -2975,6 +2989,12 @@ _scsih_block_io_device(struct MPT3SAS_ADAPTER *ioc, u16 handle)
 			continue;
 		if (sas_device->pend_sas_rphy_add)
 			continue;
+		if (sas_device_priv_data->ignore_delay_remove) {
+			sdev_printk(KERN_INFO, sdev,
+			"%s skip device_block for SES handle(0x%04x)\n",
+			__func__, sas_device_priv_data->sas_target->handle);
+			continue;
+		}
 		_scsih_internal_device_block(sdev, sas_device_priv_data);
 	}