Commit 086c4802 authored by Finn Thain's avatar Finn Thain Committed by Martin K. Petersen
Browse files

scsi: NCR5380: Handle BSY signal loss during information transfer phases 



Improve robustness by checking for a lost BSY signal during the information
transfer loop. The status register is being polled anyway, so a BSY check
costs nothing. BSY signal loss could be caused by a target error or a
kicked plug etc. A bus reset is another possibility but that is already
handled and hostdata->connected would be NULL.

Tested-by: default avatarStan Johnson <userm57@yahoo.com>
Signed-off-by: default avatarFinn Thain <fthain@linux-m68k.org>
Link: https://lore.kernel.org/r/d253dddaf4d9bc17b8ee02ea2b731d92f25b16f1.1723001788.git.fthain@linux-m68k.org


Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
parent 1c71065d

drivers/scsi/NCR5380.c

+14 −8
Original line number Diff line number Diff line
@@ -1244,8 +1244,6 @@ static bool NCR5380_select(struct Scsi_Host *instance, struct scsi_cmnd *cmd) 
 * is in same phase.

 *

 * Also, *phase, *count, *data are modified in place.

 *

 * XXX Note : handling for bus free may be useful.

 */



/*
@@ -1277,8 +1275,8 @@ static int NCR5380_transfer_pio(struct Scsi_Host *instance, 
		 * valid

		 */



		if (NCR5380_poll_politely(hostdata, STATUS_REG, SR_REQ, SR_REQ,

					  HZ * can_sleep) < 0)

		if (NCR5380_poll_politely(hostdata, STATUS_REG, SR_REQ | SR_BSY,

					  SR_REQ | SR_BSY, HZ * can_sleep) < 0)

			break;



		dsprintk(NDEBUG_HANDSHAKE, instance, "REQ asserted\n");
@@ -1666,9 +1664,6 @@ static int NCR5380_transfer_dma(struct Scsi_Host *instance, 
 * Side effects : SCSI things happen, the disconnected queue will be

 * modified if a command disconnects, *instance->connected will

 * change.

 *

 * XXX Note : we need to watch for bus free or a reset condition here

 * to recover from an unexpected bus free condition.

 */



static void NCR5380_information_transfer(struct Scsi_Host *instance)
@@ -2009,9 +2004,20 @@ static void NCR5380_information_transfer(struct Scsi_Host *instance) 
				NCR5380_dprint(NDEBUG_ANY, instance);

			} /* switch(phase) */

		} else {

			int err;



			spin_unlock_irq(&hostdata->lock);

			NCR5380_poll_politely(hostdata, STATUS_REG, SR_REQ, SR_REQ, HZ);

			err = NCR5380_poll_politely(hostdata, STATUS_REG,

						    SR_REQ, SR_REQ, HZ);

			spin_lock_irq(&hostdata->lock);



			if (err < 0 && hostdata->connected &&

			    !(NCR5380_read(STATUS_REG) & SR_BSY)) {

				scmd_printk(KERN_ERR, hostdata->connected,

					    "BSY signal lost\n");

				do_reset(instance);

				bus_reset_cleanup(instance);

			}

		}

	}

}