[PATCH v2 14/72] ncr5380: Use return instead of goto in NCR5380_select()

Finn Thain
2015-12-06T04:04:11Z

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The "failed" label in NCR5380_select() is not helpful. Some failures
return 0, others -1. Use return instead of goto to improve clarity and
brevity, like atari_NCR5380.c does. Fix the relevant comments.

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

---
drivers/scsi/NCR5380.c | 30 ++++++++----------------------
drivers/scsi/atari_NCR5380.c | 6 +++---
2 files changed, 11 insertions(+), 25 deletions(-)

Index: linux/drivers/scsi/NCR5380.c
===================================================================
--- linux.orig/drivers/scsi/NCR5380.c 2015-12-06 12:29:40.000000000 +1100
+++ linux/drivers/scsi/NCR5380.c 2015-12-06 12:29:42.000000000 +1100
@@ -997,16 +997,6 @@ static void NCR5380_main(struct work_str
*/
dprintk(NDEBUG_MAIN|NDEBUG_QUEUES, "scsi%d : main() : command for target %d lun %llu removed from issue_queue\n", instance->host_no, tmp->device->id, tmp->device->lun);

- /*
- * A successful selection is defined as one that
- * leaves us with the command connected and
- * in hostdata->connected, OR has terminated the
- * command.
- *
- * With successful commands, we fall through
- * and see if we can do an information transfer,
- * with failures we will restart.
- */
hostdata->selecting = NULL;
/* RvC: have to preset this to indicate a new command is being performed */

@@ -1162,9 +1152,10 @@ static irqreturn_t NCR5380_intr(int dumm
* Inputs : instance - instantiation of the 5380 driver on which this
* target lives, cmd - SCSI command to execute.
*
- * Returns : -1 if selection could not execute for some reason,
- * 0 if selection succeeded or failed because the target
- * did not respond.
+ * Returns : -1 if selection failed but should be retried.
+ * 0 if selection failed and should not be retried.
+ * 0 if selection succeeded completely (hostdata->connected == cmd).
+ * 0 if selection in progress (hostdata->selecting == cmd).
*
* Side effects :
* If bus busy, arbitration failed, etc, NCR5380_select() will exit
@@ -1224,7 +1215,7 @@ static int NCR5380_select(struct Scsi_Ho
printk(KERN_DEBUG "scsi: arbitration timeout at %d\n", __LINE__);
NCR5380_write(MODE_REG, MR_BASE);
NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
- goto failed;
+ return -1;
}

dprintk(NDEBUG_ARBITRATION, "scsi%d : arbitration complete\n", instance->host_no);
@@ -1242,7 +1233,7 @@ static int NCR5380_select(struct Scsi_Ho
if ((NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST) || (NCR5380_read(CURRENT_SCSI_DATA_REG) & hostdata->id_higher_mask) || (NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST)) {
NCR5380_write(MODE_REG, MR_BASE);
dprintk(NDEBUG_ARBITRATION, "scsi%d : lost arbitration, deasserting MR_ARBITRATE\n", instance->host_no);
- goto failed;
+ return -1;
}
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_SEL);

@@ -1255,7 +1246,7 @@ static int NCR5380_select(struct Scsi_Ho
NCR5380_write(MODE_REG, MR_BASE);
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
dprintk(NDEBUG_ARBITRATION, "scsi%d : lost arbitration, deasserting ICR_ASSERT_SEL\n", instance->host_no);
- goto failed;
+ return -1;
}
/*
* Again, bus clear + bus settle time is 1.2us, however, this is
@@ -1412,7 +1403,7 @@ part2:
if(err) {
printk(KERN_ERR "scsi%d: timeout at NCR5380.c:%d\n", instance->host_no, __LINE__);
NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
- goto failed;
+ return -1;
}

dprintk(NDEBUG_SELECTION, "scsi%d : target %d selected, going into MESSAGE OUT phase.\n", instance->host_no, cmd->device->id);
@@ -1433,11 +1424,6 @@ part2:
initialize_SCp(cmd);

return 0;
-
- /* Selection failed */
-failed:
- return -1;
-
}

/*
Index: linux/drivers/scsi/atari_NCR5380.c
===================================================================
--- linux.orig/drivers/scsi/atari_NCR5380.c 2015-12-06 12:29:40.000000000 +1100
+++ linux/drivers/scsi/atari_NCR5380.c 2015-12-06 12:29:42.000000000 +1100
@@ -1382,9 +1382,9 @@ static irqreturn_t NCR5380_intr(int irq,
* Inputs : instance - instantiation of the 5380 driver on which this
* target lives, cmd - SCSI command to execute.
*
- * Returns : -1 if selection could not execute for some reason,
- * 0 if selection succeeded or failed because the target
- * did not respond.
+ * Returns : -1 if selection failed but should be retried.
+ * 0 if selection failed and should not be retried.
+ * 0 if selection succeeded completely (hostdata->connected == cmd).
*
* Side effects :
* If bus busy, arbitration failed, etc, NCR5380_select() will exit