scsi: NCR5380: Always re-enable reselection interrupt

The reselection interrupt gets disabled during selection and must be
re-enabled when hostdata->connected becomes NULL. If it isn't re-enabled a
disconnected command may time-out or the target may wedge the bus while
trying to reselect the host. This can happen after a command is aborted.

Fix this by enabling the reselection interrupt in NCR5380_main() after
calls to NCR5380_select() and NCR5380_information_transfer() return.

Cc: Michael Schmitz <schmitzmic@gmail.com>
Cc: stable@vger.kernel.org # v4.9+
Fixes: 8b00c3d5 ("ncr5380: Implement new eh_abort_handler")
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Tested-by: Stan Johnson <userm57@yahoo.com>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/NCR5380.c

@@ -709,6 +709,8 @@ static void NCR5380_main(struct work_struct *work)
 			NCR5380_information_transfer(instance);
 			done = 0;
 		}
+		if (!hostdata->connected)
+			NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
 		spin_unlock_irq(&hostdata->lock);
 		if (!done)
 			cond_resched();
@@ -1110,8 +1112,6 @@ static bool NCR5380_select(struct Scsi_Host *instance, struct scsi_cmnd *cmd)
 		spin_lock_irq(&hostdata->lock);
 		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
 		NCR5380_reselect(instance);
-		if (!hostdata->connected)
-			NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
 		shost_printk(KERN_ERR, instance, "reselection after won arbitration?\n");
 		goto out;
 	}
@@ -1119,7 +1119,6 @@ static bool NCR5380_select(struct Scsi_Host *instance, struct scsi_cmnd *cmd)
 	if (err < 0) {
 		spin_lock_irq(&hostdata->lock);
 		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
-		NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
 
 		/* Can't touch cmd if it has been reclaimed by the scsi ML */
 		if (!hostdata->selecting)
@@ -1157,7 +1156,6 @@ static bool NCR5380_select(struct Scsi_Host *instance, struct scsi_cmnd *cmd)
 	if (err < 0) {
 		shost_printk(KERN_ERR, instance, "select: REQ timeout\n");
 		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
-		NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
 		goto out;
 	}
 	if (!hostdata->selecting) {
@@ -1826,9 +1824,6 @@ static void NCR5380_information_transfer(struct Scsi_Host *instance)
 					 */
 					NCR5380_write(TARGET_COMMAND_REG, 0);
 
-					/* Enable reselect interrupts */
-					NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
-
 					maybe_release_dma_irq(instance);
 					return;
 				case MESSAGE_REJECT:
@@ -1860,8 +1855,6 @@ static void NCR5380_information_transfer(struct Scsi_Host *instance)
 					 */
 					NCR5380_write(TARGET_COMMAND_REG, 0);
 
-					/* Enable reselect interrupts */
-					NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
 #ifdef SUN3_SCSI_VME
 					dregs->csr |= CSR_DMA_ENABLE;
 #endif
@@ -1964,7 +1957,6 @@ static void NCR5380_information_transfer(struct Scsi_Host *instance)
 					cmd->result = DID_ERROR << 16;
 					complete_cmd(instance, cmd);
 					maybe_release_dma_irq(instance);
-					NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
 					return;
 				}
 				msgout = NOP;