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 Reviewed-by: Hannes Reinecke Tested-by: Ondrej Zary Tested-by: Michael Schmitz --- 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 2016-01-03 16:03:17.000000000 +1100 +++ linux/drivers/scsi/NCR5380.c 2016-01-03 16:03:18.000000000 +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 2016-01-03 16:03:17.000000000 +1100 +++ linux/drivers/scsi/atari_NCR5380.c 2016-01-03 16:03:18.000000000 +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) */ -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/