diff options
author | Finn Thain <fthain@telegraphics.com.au> | 2016-01-03 16:05:19 +1100 |
---|---|---|
committer | Martin K. Petersen <martin.petersen@oracle.com> | 2016-01-06 21:42:55 -0500 |
commit | 4d029e9ae9c382b149b16632f49970d8b215e2da (patch) | |
tree | ecd48ef21f2f10c7020adebb701952d37b29c4bc /drivers/scsi/NCR5380.c | |
parent | cf13b0837d7da2f3dce96e1f364fade13c8648ba (diff) | |
download | linux-stable-4d029e9ae9c382b149b16632f49970d8b215e2da.tar.gz linux-stable-4d029e9ae9c382b149b16632f49970d8b215e2da.tar.bz2 linux-stable-4d029e9ae9c382b149b16632f49970d8b215e2da.zip |
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>
Diffstat (limited to 'drivers/scsi/NCR5380.c')
-rw-r--r-- | drivers/scsi/NCR5380.c | 19 |
1 files changed, 5 insertions, 14 deletions
diff --git a/drivers/scsi/NCR5380.c b/drivers/scsi/NCR5380.c index d51aad3a3bfa..103c23e6d565 100644 --- 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 |