ncr5380: Eliminate USLEEP_WAITLONG delay

Linux 2.1.105 introduced the USLEEP_WAITLONG delay, apparently "needed for
Mustek scanners". It is intended to stall the issue queue for 5 seconds.
There are a number of problems with this.

1. Only g_NCR5380 enables the delay, which implies that the other five
   drivers using the NCR5380.c core driver remain incompatible with
   Mustek scanners.

2. The delay is not implemented by atari_NCR5380.c, which is problematic
   for re-unifying the two core driver forks.

3. The delay is implemented using NCR5380_set_timer() which makes it
   unreliable. A new command queued by the mid-layer cancels the delay.

4. The delay is applied indiscriminately in several situations in which
   NCR5380_select() returns -1. These are-- reselection by the target,
   failure of the target to assert BSY, and failure of the target to
   assert REQ. It's clear from the comments that USLEEP_WAITLONG is not
   relevant to the reselection case. And reportedly, these scanners do
   not disconnect.

5. atari_NCR5380.c was forked before Linux 2.1.105, so it was spared some
   of the damage done to NCR5380.c. In this case, the atari_NCR5380.c core
   driver was more standard-compliant and may not have needed any
   workaround like the USLEEP_WAITLONG kludge. The compliance issue was
   addressed in the previous patch.

If these scanners still don't work, we need a better solution. Retrying
selection until EH aborts a command offers equivalent robustness. Bugs in
the existing driver prevent EH working correctly but this is addressed in
a subsequent patch. Remove USLEEP_WAITLONG.

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Tested-by: Ondrej Zary <linux@rainbow-software.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/NCR5380.c b/drivers/scsi/NCR5380.c
index d51aad3a3bfa160801e2e871d271465c328aff46..103c23e6d565c99b8c9c5def183684e5e3dd56dc 100644 (file)
--- a/drivers/scsi/NCR5380.c
+++ b/drivers/scsi/NCR5380.c
@@ -468,10 +468,6 @@ static void NCR5380_print_phase(struct Scsi_Host *instance)
 #ifndef USLEEP_POLL
 #define USLEEP_POLL msecs_to_jiffies(200)
 #endif
-#ifndef USLEEP_WAITLONG
-/* RvC: (reasonable time to wait on select error) */
-#define USLEEP_WAITLONG USLEEP_SLEEP
-#endif
 
 /* 
  * Function : int should_disconnect (unsigned char cmd)
@@ -619,8 +615,8 @@ static void prepare_info(struct Scsi_Host *instance)
                 "can_queue %d, cmd_per_lun %d, "
                 "sg_tablesize %d, this_id %d, "
                 "flags { %s%s%s%s}, "
-#if defined(USLEEP_POLL) && defined(USLEEP_WAITLONG)
-                "USLEEP_POLL %lu, USLEEP_WAITLONG %lu, "
+#if defined(USLEEP_POLL) && defined(USLEEP_SLEEP)
+                "USLEEP_POLL %lu, USLEEP_SLEEP %lu, "
 #endif
                 "options { %s} ",
                 instance->hostt->name, instance->io_port, instance->n_io_port,
@@ -631,8 +627,8 @@ static void prepare_info(struct Scsi_Host *instance)
                 hostdata->flags & FLAG_DTC3181E      ? "DTC3181E "      : "",
                 hostdata->flags & FLAG_NO_PSEUDO_DMA ? "NO_PSEUDO_DMA " : "",
                 hostdata->flags & FLAG_TOSHIBA_DELAY ? "TOSHIBA_DELAY "  : "",
-#if defined(USLEEP_POLL) && defined(USLEEP_WAITLONG)
-                USLEEP_POLL, USLEEP_WAITLONG,
+#if defined(USLEEP_POLL) && defined(USLEEP_SLEEP)
+                USLEEP_POLL, USLEEP_SLEEP,
 #endif
 #ifdef AUTOPROBE_IRQ
                 "AUTOPROBE_IRQ "
@@ -1030,15 +1026,10 @@ static void NCR5380_main(struct work_struct *work)
                        if (!NCR5380_select(instance, tmp)) {
                                /* OK or bad target */
                        } else {
-                               /* RvC: device failed, so we wait a long time
-                                  this is needed for Mustek scanners, that
-                                  do not respond to commands immediately
-                                  after a scan */
-                               printk(KERN_DEBUG "scsi%d: device %d did not respond in time\n", instance->host_no, tmp->device->id);
                                LIST(tmp, hostdata->issue_queue);
                                tmp->host_scribble = (unsigned char *) hostdata->issue_queue;
                                hostdata->issue_queue = tmp;
-                               NCR5380_set_timer(hostdata, USLEEP_WAITLONG);
+                               done = 0;
                        }
                }       /* if hostdata->selecting */
                if (hostdata->connected

diff --git a/drivers/scsi/g_NCR5380.c b/drivers/scsi/g_NCR5380.c
index ffbb07b0e9e8188d727627de9cc05c381fcc50fa..fa9f6d41548bf4322214d9fa8c6084a562957e75 100644 (file)
--- a/drivers/scsi/g_NCR5380.c
+++ b/drivers/scsi/g_NCR5380.c
@@ -59,7 +59,6 @@
 /* settings for DTC3181E card with only Mustek scanner attached */
 #define USLEEP_POLL    msecs_to_jiffies(10)
 #define USLEEP_SLEEP   msecs_to_jiffies(200)
-#define USLEEP_WAITLONG        msecs_to_jiffies(5000)
 
 #define AUTOPROBE_IRQ