* Re: [PATCH 1/3] aic79xx: convert qfrozen to atomic_t
@ 2006-02-08 10:16 Emmanuel Fusté
2006-02-08 10:52 ` Hannes Reinecke
0 siblings, 1 reply; 8+ messages in thread
From: Emmanuel Fusté @ 2006-02-08 10:16 UTC (permalink / raw)
Cc: hare, hch, linux-scsi
> On Tue, Feb 07, 2006 at 12:30:55PM +0100, Hannes Reinecke wrote:
> > As in
> >
> > void
> > ahd_freeze_simq(struct ahd_softc *ahd)
> > {
> > scsi_block_requests(ahd->platform_data->host);
> > }
> >
> > ?
>
> Yes.
>
Does it mean we could simply remove the platform_data->qfrozen
flag/counter ?
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^ permalink raw reply [flat|nested] 8+ messages in thread* [PATCH 1/3] aic79xx: convert qfrozen to atomic_t
@ 2006-02-07 7:52 Hannes Reinecke
2006-02-07 11:00 ` Christoph Hellwig
2006-02-07 18:57 ` Christoph Hellwig
0 siblings, 2 replies; 8+ messages in thread
From: Hannes Reinecke @ 2006-02-07 7:52 UTC (permalink / raw)
To: SCSI Mailing List; +Cc: emmanuel.fuste
[-- Attachment #1: Type: text/plain, Size: 406 bytes --]
This patch converts platform_data->qfrozen to atomic_t.
This way we can get rid of ahd_lock / ahd_unlock for the
accessor functions; it also fixes some deadlocks in the
recovery code (again).
Signed-off-by: Hannes Reinecke <hare@suse.de>
--
Dr. Hannes Reinecke hare@suse.de
SuSE Linux Products GmbH S390 & zSeries
Maxfeldstraße 5 +49 911 74053 688
90409 Nürnberg http://www.suse.de
[-- Attachment #2: 0001-aic79xx-convert-qfrozen-to-atomic_t.txt --]
[-- Type: text/plain, Size: 4195 bytes --]
Subject: [PATCH 1/3] aic79xx: convert qfrozen to atomic_t
This patch converts platform_data->qfrozen to atomic_t.
This way we can get rid of ahd_lock / ahd_unlock for the
accessor functions; it also fixes some deadlocks in the
recovery code (again).
Signed-off-by: Hannes Reinecke <hare@suse.de>
---
drivers/scsi/aic7xxx/aic79xx_osm.c | 42 +++++++++---------------------------
drivers/scsi/aic7xxx/aic79xx_osm.h | 2 +-
2 files changed, 11 insertions(+), 33 deletions(-)
872e277a460c57d74bfb478fdbc86aae02f37198
diff --git a/drivers/scsi/aic7xxx/aic79xx_osm.c b/drivers/scsi/aic7xxx/aic79xx_osm.c
index 78c8338..bd2be6a 100644
--- a/drivers/scsi/aic7xxx/aic79xx_osm.c
+++ b/drivers/scsi/aic7xxx/aic79xx_osm.c
@@ -453,18 +453,15 @@ ahd_linux_queue(struct scsi_cmnd * cmd,
struct ahd_softc *ahd;
struct ahd_linux_device *dev = scsi_transport_device_data(cmd->device);
int rtn = SCSI_MLQUEUE_HOST_BUSY;
- unsigned long flags;
ahd = *(struct ahd_softc **)cmd->device->host->hostdata;
- ahd_lock(ahd, &flags);
- if (ahd->platform_data->qfrozen == 0) {
+ if (!atomic_read(&ahd->platform_data->qfrozen)) {
cmd->scsi_done = scsi_done;
cmd->result = CAM_REQ_INPROG << 16;
rtn = ahd_linux_run_command(ahd, dev, cmd);
}
- ahd_unlock(ahd, &flags);
return rtn;
}
@@ -691,10 +688,8 @@ ahd_linux_bus_reset(struct scsi_cmnd *cm
printf("%s: Bus reset called for cmd %p\n",
ahd_name(ahd), cmd);
#endif
- ahd_lock(ahd, &s);
found = ahd_reset_channel(ahd, scmd_channel(cmd) + 'A',
/*initiate reset*/TRUE);
- ahd_unlock(ahd, &s);
if (bootverbose)
printf("%s: SCSI bus reset delivered. "
@@ -1194,6 +1189,7 @@ ahd_platform_alloc(struct ahd_softc *ahd
memset(ahd->platform_data, 0, sizeof(struct ahd_platform_data));
ahd->platform_data->irq = AHD_LINUX_NOIRQ;
ahd_lockinit(ahd);
+ atomic_set(&ahd->platform_data->qfrozen, 0);
init_MUTEX_LOCKED(&ahd->platform_data->eh_sem);
ahd->seltime = (aic79xx_seltime & 0x3) << 4;
return (0);
@@ -1443,6 +1439,9 @@ ahd_linux_run_command(struct ahd_softc *
struct ahd_tmode_tstate *tstate;
u_int col_idx;
uint16_t mask;
+ unsigned long flags;
+
+ ahd_lock(ahd, &flags);
/*
* Get an scb to use.
@@ -1458,6 +1457,7 @@ ahd_linux_run_command(struct ahd_softc *
}
if ((scb = ahd_get_scb(ahd, col_idx)) == NULL) {
ahd->flags |= AHD_RESOURCE_SHORTAGE;
+ ahd_unlock(ahd, &flags);
return SCSI_MLQUEUE_HOST_BUSY;
}
@@ -1583,6 +1583,8 @@ ahd_linux_run_command(struct ahd_softc *
scb->flags |= SCB_ACTIVE;
ahd_queue_scb(ahd, scb);
+ ahd_unlock(ahd, &flags);
+
return 0;
}
@@ -2051,38 +2053,14 @@ ahd_freeze_simq(struct ahd_softc *ahd)
{
unsigned long s;
- ahd_lock(ahd, &s);
- ahd->platform_data->qfrozen++;
- if (ahd->platform_data->qfrozen == 1) {
+ if (!atomic_inc_and_test(&ahd->platform_data->qfrozen))
scsi_block_requests(ahd->platform_data->host);
- ahd_platform_abort_scbs(ahd, CAM_TARGET_WILDCARD, ALL_CHANNELS,
- CAM_LUN_WILDCARD, SCB_LIST_NULL,
- ROLE_INITIATOR, CAM_REQUEUE_REQ);
- }
- ahd_unlock(ahd, &s);
}
void
ahd_release_simq(struct ahd_softc *ahd)
{
- u_long s;
- int unblock_reqs;
-
- unblock_reqs = 0;
- ahd_lock(ahd, &s);
- if (ahd->platform_data->qfrozen > 0)
- ahd->platform_data->qfrozen--;
- if (ahd->platform_data->qfrozen == 0) {
- unblock_reqs = 1;
- }
- ahd_unlock(ahd, &s);
- /*
- * There is still a race here. The mid-layer
- * should keep its own freeze count and use
- * a bottom half handler to run the queues
- * so we can unblock with our own lock held.
- */
- if (unblock_reqs)
+ if (atomic_dec_and_test(&ahd->platform_data->qfrozen))
scsi_unblock_requests(ahd->platform_data->host);
}
diff --git a/drivers/scsi/aic7xxx/aic79xx_osm.h b/drivers/scsi/aic7xxx/aic79xx_osm.h
index 9cb1013..1f60590 100644
--- a/drivers/scsi/aic7xxx/aic79xx_osm.h
+++ b/drivers/scsi/aic7xxx/aic79xx_osm.h
@@ -381,7 +381,7 @@ struct ahd_platform_data {
struct scsi_target *starget[AHD_NUM_TARGETS];
spinlock_t spin_lock;
- u_int qfrozen;
+ atomic_t qfrozen;
struct semaphore eh_sem;
struct Scsi_Host *host; /* pointer to scsi host */
#define AHD_LINUX_NOIRQ ((uint32_t)~0)
--
1.1.3
^ permalink raw reply related [flat|nested] 8+ messages in thread* Re: [PATCH 1/3] aic79xx: convert qfrozen to atomic_t
2006-02-07 7:52 Hannes Reinecke
@ 2006-02-07 11:00 ` Christoph Hellwig
2006-02-07 11:30 ` Hannes Reinecke
2006-02-07 18:57 ` Christoph Hellwig
1 sibling, 1 reply; 8+ messages in thread
From: Christoph Hellwig @ 2006-02-07 11:00 UTC (permalink / raw)
To: Hannes Reinecke; +Cc: SCSI Mailing List, emmanuel.fuste
On Tue, Feb 07, 2006 at 08:52:50AM +0100, Hannes Reinecke wrote:
> This patch converts platform_data->qfrozen to atomic_t.
> This way we can get rid of ahd_lock / ahd_unlock for the
> accessor functions; it also fixes some deadlocks in the
> recovery code (again).
Is ahd_freeze_simq called recursively at all? If not it would be much
better to just kill it completely and just rely on the block layer, as
we do in all the other drivers.
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH 1/3] aic79xx: convert qfrozen to atomic_t
2006-02-07 11:00 ` Christoph Hellwig
@ 2006-02-07 11:30 ` Hannes Reinecke
2006-02-07 18:57 ` Christoph Hellwig
0 siblings, 1 reply; 8+ messages in thread
From: Hannes Reinecke @ 2006-02-07 11:30 UTC (permalink / raw)
To: Christoph Hellwig; +Cc: SCSI Mailing List, emmanuel.fuste
Christoph Hellwig wrote:
> On Tue, Feb 07, 2006 at 08:52:50AM +0100, Hannes Reinecke wrote:
>> This patch converts platform_data->qfrozen to atomic_t.
>> This way we can get rid of ahd_lock / ahd_unlock for the
>> accessor functions; it also fixes some deadlocks in the
>> recovery code (again).
>
> Is ahd_freeze_simq called recursively at all? If not it would be much
> better to just kill it completely and just rely on the block layer, as
> we do in all the other drivers.
>
As in
void
ahd_freeze_simq(struct ahd_softc *ahd)
{
scsi_block_requests(ahd->platform_data->host);
}
?
Hmm. Looks as if this could work ...
Lemme check.
Cheers,
Hannes
--
Dr. Hannes Reinecke hare@suse.de
SuSE Linux Products GmbH S390 & zSeries
Maxfeldstraße 5 +49 911 74053 688
90409 Nürnberg http://www.suse.de
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^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH 1/3] aic79xx: convert qfrozen to atomic_t
2006-02-07 7:52 Hannes Reinecke
2006-02-07 11:00 ` Christoph Hellwig
@ 2006-02-07 18:57 ` Christoph Hellwig
2006-02-08 9:42 ` Hannes Reinecke
1 sibling, 1 reply; 8+ messages in thread
From: Christoph Hellwig @ 2006-02-07 18:57 UTC (permalink / raw)
To: Hannes Reinecke; +Cc: SCSI Mailing List, emmanuel.fuste
On Tue, Feb 07, 2006 at 08:52:50AM +0100, Hannes Reinecke wrote:
> This patch converts platform_data->qfrozen to atomic_t.
> This way we can get rid of ahd_lock / ahd_unlock for the
> accessor functions; it also fixes some deadlocks in the
> recovery code (again).
While we're at it there's also a qfrozen variable in the ahd_linux_device
structure. Since the driver lost it's internal queueing it and the
surrounding core are totally unused.
Index: linux-2.6/drivers/scsi/aic7xxx/aic79xx_osm.c
===================================================================
--- linux-2.6.orig/drivers/scsi/aic7xxx/aic79xx_osm.c 2006-01-31 12:23:38.000000000 +0100
+++ linux-2.6/drivers/scsi/aic7xxx/aic79xx_osm.c 2006-02-07 19:52:47.000000000 +0100
@@ -1290,12 +1290,6 @@
now_queuing = AHD_DEV_Q_TAGGED;
break;
}
- if ((dev->flags & AHD_DEV_FREEZE_TIL_EMPTY) == 0
- && (was_queuing != now_queuing)
- && (dev->active != 0)) {
- dev->flags |= AHD_DEV_FREEZE_TIL_EMPTY;
- dev->qfrozen++;
- }
dev->flags &= ~(AHD_DEV_Q_BASIC|AHD_DEV_Q_TAGGED|AHD_DEV_PERIODIC_OTAG);
if (now_queuing) {
@@ -1705,10 +1699,7 @@
dev = scb->platform_data->dev;
dev->active--;
dev->openings++;
- if ((cmd->result & (CAM_DEV_QFRZN << 16)) != 0) {
- cmd->result &= ~(CAM_DEV_QFRZN << 16);
- dev->qfrozen--;
- }
+
ahd_linux_unmap_scb(ahd, scb);
/*
Index: linux-2.6/drivers/scsi/aic7xxx/aic79xx_osm.h
===================================================================
--- linux-2.6.orig/drivers/scsi/aic7xxx/aic79xx_osm.h 2006-01-31 12:23:38.000000000 +0100
+++ linux-2.6/drivers/scsi/aic7xxx/aic79xx_osm.h 2006-02-07 19:52:57.000000000 +0100
@@ -264,7 +264,6 @@
*/
typedef enum {
- AHD_DEV_FREEZE_TIL_EMPTY = 0x02, /* Freeze queue until active == 0 */
AHD_DEV_Q_BASIC = 0x10, /* Allow basic device queuing */
AHD_DEV_Q_TAGGED = 0x20, /* Allow full SCSI2 command queueing */
AHD_DEV_PERIODIC_OTAG = 0x40, /* Send OTAG to prevent starvation */
@@ -291,12 +290,6 @@
int openings;
/*
- * A positive count indicates that this
- * device's queue is halted.
- */
- u_int qfrozen;
-
- /*
* Cumulative command counter.
*/
u_long commands_issued;
@@ -870,10 +863,6 @@
static __inline void
ahd_freeze_scb(struct scb *scb)
{
- if ((scb->io_ctx->result & (CAM_DEV_QFRZN << 16)) == 0) {
- scb->io_ctx->result |= CAM_DEV_QFRZN << 16;
- scb->platform_data->dev->qfrozen++;
- }
}
void ahd_platform_set_tags(struct ahd_softc *ahd,
Index: linux-2.6/drivers/scsi/aic7xxx/aic79xx_proc.c
===================================================================
--- linux-2.6.orig/drivers/scsi/aic7xxx/aic79xx_proc.c 2005-10-31 12:23:45.000000000 +0100
+++ linux-2.6/drivers/scsi/aic7xxx/aic79xx_proc.c 2006-02-07 18:12:11.000000000 +0100
@@ -255,7 +255,6 @@
copy_info(info, "\t\tCommands Active %d\n", dev->active);
copy_info(info, "\t\tCommand Openings %d\n", dev->openings);
copy_info(info, "\t\tMax Tagged Openings %d\n", dev->maxtags);
- copy_info(info, "\t\tDevice Queue Frozen Count %d\n", dev->qfrozen);
}
static int
^ permalink raw reply [flat|nested] 8+ messages in thread* Re: [PATCH 1/3] aic79xx: convert qfrozen to atomic_t
2006-02-07 18:57 ` Christoph Hellwig
@ 2006-02-08 9:42 ` Hannes Reinecke
0 siblings, 0 replies; 8+ messages in thread
From: Hannes Reinecke @ 2006-02-08 9:42 UTC (permalink / raw)
To: Christoph Hellwig; +Cc: SCSI Mailing List, emmanuel.fuste
Christoph Hellwig wrote:
> On Tue, Feb 07, 2006 at 08:52:50AM +0100, Hannes Reinecke wrote:
>> This patch converts platform_data->qfrozen to atomic_t.
>> This way we can get rid of ahd_lock / ahd_unlock for the
>> accessor functions; it also fixes some deadlocks in the
>> recovery code (again).
>
> While we're at it there's also a qfrozen variable in the ahd_linux_device
> structure. Since the driver lost it's internal queueing it and the
> surrounding core are totally unused.
>
Not quite sure (yet) whether we can do this.
dev->qfrozen is also used during error recovery to prevent the SCB being
reused accidentally.
And as the error recovery is totally buggered anyway I'm loath to
dead-fix it even more. I'll have to investigate that.
But the platform->qfrozen flag can indeed be removed. Just calling
scsi_block_request() is enough here.
Cheers,
Hannes
--
Dr. Hannes Reinecke hare@suse.de
SuSE Linux Products GmbH S390 & zSeries
Maxfeldstraße 5 +49 911 74053 688
90409 Nürnberg http://www.suse.de
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^ permalink raw reply [flat|nested] 8+ messages in thread
end of thread, other threads:[~2006-02-08 10:52 UTC | newest]
Thread overview: 8+ messages (download: mbox.gz follow: Atom feed
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2006-02-08 10:16 [PATCH 1/3] aic79xx: convert qfrozen to atomic_t Emmanuel Fusté
2006-02-08 10:52 ` Hannes Reinecke
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2006-02-07 11:00 ` Christoph Hellwig
2006-02-07 11:30 ` Hannes Reinecke
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2006-02-08 9:42 ` Hannes Reinecke
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