[PATCH v2 16/72] ncr5380: Proceed with next command after NCR5380_select() calls scsi_done

Finn Thain
2015-12-06T04:03:32Z

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If a target disappears from the SCSI bus, NCR5380_select() may
subsequently fail with a time-out. In this situation, scsi_done is
called and NCR5380_select() returns 0. Both hostdata->connected and
hostdata->selecting are NULL and the main loop should proceed with
the next command in the issue queue. Clarify this logic.

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.com>

---

Good code style would be,

if (this) {
/* do stuff */
}

rather than,

if (!this) {
} else {
/* do stuff */
}

But I've used the latter form at this point in the series for a cleaner
diff between NCR5380.c and atari_NC5380.c, making it easier to gradually
reduce discrepancies. Code style gets fixed up along the way.

---
drivers/scsi/NCR5380.c | 8 ++++++--
drivers/scsi/atari_NCR5380.c | 8 ++++----
2 files changed, 10 insertions(+), 6 deletions(-)

Index: linux/drivers/scsi/NCR5380.c
===================================================================
--- linux.orig/drivers/scsi/NCR5380.c 2015-12-06 12:29:44.000000000 +1100
+++ linux/drivers/scsi/NCR5380.c 2015-12-06 12:29:46.000000000 +1100
@@ -1007,14 +1007,18 @@ static void NCR5380_main(struct work_str
*/

if (!NCR5380_select(instance, tmp)) {
- break;
+ /* OK or bad target */
} else {
+ /* Need to retry */
LIST(tmp, hostdata->issue_queue);
tmp->host_scribble = (unsigned char *) hostdata->issue_queue;
hostdata->issue_queue = tmp;
done = 0;
dprintk(NDEBUG_MAIN|NDEBUG_QUEUES, "scsi%d : main(): select() failed, returned to issue_queue\n", instance->host_no);
}
+ if (hostdata->connected ||
+ hostdata->selecting)
+ break;
/* lock held here still */
} /* if target/lun is not busy */
} /* for */
@@ -1024,7 +1028,7 @@ static void NCR5380_main(struct work_str
tmp = (struct scsi_cmnd *) hostdata->selecting;
/* Selection will drop and retake the lock */
if (!NCR5380_select(instance, tmp)) {
- /* Ok ?? */
+ /* OK or bad target */
} else {
/* RvC: device failed, so we wait a long time
this is needed for Mustek scanners, that
Index: linux/drivers/scsi/atari_NCR5380.c
===================================================================
--- linux.orig/drivers/scsi/atari_NCR5380.c 2015-12-06 12:29:44.000000000 +1100
+++ linux/drivers/scsi/atari_NCR5380.c 2015-12-06 12:29:46.000000000 +1100
@@ -1139,13 +1139,13 @@ static void NCR5380_main(struct work_str
cmd_get_tag(tmp, tmp->cmnd[0] != REQUEST_SENSE);
#endif
if (!NCR5380_select(instance, tmp)) {
+ /* OK or bad target */
local_irq_disable();
hostdata->retain_dma_intr--;
- /* release if target did not response! */
maybe_release_dma_irq(instance);
local_irq_restore(flags);
- break;
} else {
+ /* Need to retry */
local_irq_disable();
LIST(tmp, hostdata->issue_queue);
SET_NEXT(tmp, hostdata->issue_queue);
@@ -1157,9 +1157,9 @@ static void NCR5380_main(struct work_str
local_irq_restore(flags);
dprintk(NDEBUG_MAIN, "scsi%d: main(): select() failed, "
"returned to issue_queue\n", HOSTNO);
- if (hostdata->connected)
- break;
}
+ if (hostdata->connected)
+ break;
} /* if target/lun/target queue is not busy */
} /* for issue_queue */
} /* if (!hostdata->connected) */