[5270] in linux-scsi channel archive
Re: scsi code and jiffy wraps
daemon@ATHENA.MIT.EDU (Andrea Arcangeli)
Thu Dec 3 14:08:48 1998
Date: Thu, 3 Dec 1998 13:50:55 +0100 (CET)
From: Andrea Arcangeli <andrea@e-mind.com>
To: Linus Torvalds <torvalds@transmeta.com>
cc: linux-scsi@vger.rutgers.edu, eric@aib.com, linux-kernel@vger.rutgers.edu
In-Reply-To: <Pine.LNX.3.96.981203123214.1479A-100000@dragon.bogus>
On Thu, 3 Dec 1998, Andrea Arcangeli wrote:
>in. It avoids that the scsi system hangs the machine after ~0UL jiffies
>from the latest scsi reset. I tested it in the only way I was able to do.
Woops, please reject/forget the scsi-2.1.130 patch in the last email. I
fixed a little bug + a cleanup and I rediffed against 2.1.131:
Index: linux/drivers/scsi/scsi.c
diff -u linux/drivers/scsi/scsi.c:1.1.1.1 linux/drivers/scsi/scsi.c:1.1.1.1.2.3
--- linux/drivers/scsi/scsi.c:1.1.1.1 Fri Nov 20 00:02:39 1998
+++ linux/drivers/scsi/scsi.c Thu Dec 3 12:29:40 1998
@@ -30,6 +30,8 @@
* Leonard N. Zubkoff <lnz@dandelion.com>
*
* Converted cli() code to spinlocks, Ingo Molnar
+ *
+ * Jiffies wrap fixes (host->resetting), 3 Dec 1998 Andrea Arcangeli
*/
#include <linux/config.h>
@@ -1297,7 +1299,7 @@
*/
timeout = host->last_reset + MIN_RESET_DELAY;
- if (jiffies < timeout) {
+ if (host->resetting && time_before(jiffies, timeout)) {
int ticks_remaining = timeout - jiffies;
/*
* NOTE: This may be executed from within an interrupt
@@ -1310,7 +1312,7 @@
*/
spin_unlock_irq(&io_request_lock);
while (--ticks_remaining >= 0) mdelay(1+999/HZ);
- host->last_reset = jiffies - MIN_RESET_DELAY;
+ host->resetting = 0;
spin_lock_irq(&io_request_lock);
}
@@ -1367,7 +1369,7 @@
#ifdef DEBUG_DELAY
clock = jiffies + 4 * HZ;
spin_unlock_irq(&io_request_lock);
- while (jiffies < clock) barrier();
+ while (time_before(jiffies, clock)) barrier();
spin_lock_irq(&io_request_lock);
printk("done(host = %d, result = %04x) : routine at %p\n",
host->host_no, temp, host->hostt->command);
Index: linux/drivers/scsi/hosts.c
diff -u linux/drivers/scsi/hosts.c:1.1.1.1 linux/drivers/scsi/hosts.c:1.1.1.1.2.5
--- linux/drivers/scsi/hosts.c:1.1.1.1 Fri Nov 20 00:02:39 1998
+++ linux/drivers/scsi/hosts.c Thu Dec 3 12:29:39 1998
@@ -7,6 +7,8 @@
* Subsequent revisions: Eric Youngdale
*
* <drew@colorado.edu>
+ *
+ * Jiffies wrap fixes (host->resetting), 3 Dec 1998 Andrea Arcangeli
*/
@@ -581,7 +583,8 @@
next_scsi_host++;
retval->host_queue = NULL;
retval->host_wait = NULL;
- retval->last_reset = 0;
+ retval->resetting = 0;
+ /* retval->last_reset don' t need to be set because resetting is 0 -arca */
retval->irq = 0;
retval->dma_channel = 0xff;
Index: linux/drivers/scsi/hosts.h
diff -u linux/drivers/scsi/hosts.h:1.1.1.1 linux/drivers/scsi/hosts.h:1.1.1.1.2.2
--- linux/drivers/scsi/hosts.h:1.1.1.1 Fri Nov 20 00:02:39 1998
+++ linux/drivers/scsi/hosts.h Thu Dec 3 12:29:40 1998
@@ -14,6 +14,8 @@
*
* Further modified by Eric Youngdale to support multiple host adapters
* of the same type.
+ *
+ * Jiffies wrap fixes (host->resetting), 3 Dec 1998 Andrea Arcangeli
*/
#ifndef _HOSTS_H
@@ -320,6 +322,7 @@
/* public: */
unsigned short extra_bytes;
unsigned short host_no; /* Used for IOCTL_GET_IDLUN, /proc/scsi et al. */
+ int resetting; /* if set, it means that last_reset is a valid value */
unsigned long last_reset;
Index: linux/drivers/scsi/scsi_error.c
diff -u linux/drivers/scsi/scsi_error.c:1.1.1.1 linux/drivers/scsi/scsi_error.c:1.1.1.1.2.1
--- linux/drivers/scsi/scsi_error.c:1.1.1.1 Fri Nov 20 00:02:54 1998
+++ linux/drivers/scsi/scsi_error.c Fri Nov 20 00:15:31 1998
@@ -142,7 +142,6 @@
SCSI_LOG_ERROR_RECOVERY(5,printk("Clearing timer for command %p\n", SCset));
SCset->eh_timeout.data = (unsigned long) NULL;
- SCset->eh_timeout.expires = 0;
SCset->eh_timeout.function = NULL;
return rtn;
Index: linux/drivers/scsi/scsi_obsolete.c
diff -u linux/drivers/scsi/scsi_obsolete.c:1.1.1.2 linux/drivers/scsi/scsi_obsolete.c:1.1.1.1.2.5
--- linux/drivers/scsi/scsi_obsolete.c:1.1.1.2 Thu Dec 3 12:53:28 1998
+++ linux/drivers/scsi/scsi_obsolete.c Thu Dec 3 14:01:03 1998
@@ -604,21 +604,18 @@
printk("In MAYREDO, allowing %d retries, have %d\n",
SCpnt->allowed, SCpnt->retries);
#endif
- if ((++SCpnt->retries) < SCpnt->allowed)
- {
- if ((SCpnt->retries >= (SCpnt->allowed >> 1))
- /* FIXME: last_reset == 0 is allowed */
- && time_after(jiffies, SCpnt->host->last_reset
- + MIN_RESET_PERIOD)
- && !(SCpnt->flags & WAS_RESET))
- {
- printk("scsi%d channel %d : resetting for second half of retries.\n",
- SCpnt->host->host_no, SCpnt->channel);
- scsi_reset(SCpnt, SCSI_RESET_SYNCHRONOUS);
- break;
- }
-
- }
+ if (++SCpnt->retries < SCpnt->allowed &&
+ SCpnt->retries >= (SCpnt->allowed >> 1)
+ && !(SCpnt->host->resetting &&
+ time_before(jiffies, SCpnt->host->last_reset
+ + MIN_RESET_PERIOD))
+ && !(SCpnt->flags & WAS_RESET))
+ {
+ printk("scsi%d channel %d : resetting for second half of retries.\n",
+ SCpnt->host->host_no, SCpnt->channel);
+ scsi_reset(SCpnt, SCSI_RESET_SYNCHRONOUS);
+ break;
+ }
else
{
status = CMD_FINISHED;
@@ -935,6 +932,12 @@
}
host->last_reset = jiffies;
+ host->resetting = 1;
+ /*
+ * I suppose that the host reset callback will not play
+ * with the resetting field. We have just set the resetting
+ * flag here. -arca
+ */
temp = host->hostt->reset(SCpnt, reset_flags);
/*
This test allows the driver to introduce an additional bus
@@ -953,7 +956,13 @@
{
if (!host->block) host->host_busy++;
host->last_reset = jiffies;
+ host->resetting = 1;
SCpnt->flags |= (WAS_RESET | IS_RESETTING);
+ /*
+ * I suppose that the host reset callback will not play
+ * with the resetting field. We have just set the resetting
+ * flag here. -arca
+ */
temp = host->hostt->reset(SCpnt, reset_flags);
if (time_before(host->last_reset, jiffies) ||
(time_after(host->last_reset, jiffies + 20 * HZ)))
Andrea Arcangeli
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