Alan Stern wrote:
> On Fri, 16 Sep 2005, Mike Anderson wrote:
>
>
>>>This makes me suspect that the condition about host_busy == host_failed is
>>>wrong. Unfortunately I don't know why it's wrong or how to fix it.
>>>
>>>Perhaps somebody on the SCSI list can provide the answer.
>>>
>>
>>What condition are you thinking would happen if this was wrong (we are
>>getting woken up too early?)?
>
>
> Yes, that is what would happen. Or failing to go back to sleep when we
> should, which might be even worse.
>
>
>> I did a quick look and could not see changes
>>between 2.6.13 and 2.16.14-rc1 that would make these values wrong. This is
>>just a check to ensure the eh is not woken up to early. Historically in
>>older scsi eh code there used to be a panic if the error handler was woken
>>up to early. In scsi_unjam_host and a quick look at ata_scsi_error getting
>>woken up early should not cause a panic.
>>
>>I built a listfile (libata-scsi.lst) and it is probably not an exact
>>match. ..but..
>>
>>These lines in ata_scsi_error(..) appear to be close to the failure and
>>edx being zero as shown above in the oops would not be good.
>> ap->ops->eng_timeout(ap);
>> 499: 8b 50 04 mov 0x4(%eax),%edx
>> 49c: ff 52 48 call *0x48(%edx)
>>
>>Since I do not know the libata code it is unclear from doing a short
>>search how an ops pointer could get altered or if my observations are
>>correct.
>
>
> Maybe the wakeup occurred before ap->ops was set correctly, or after it
> was unset. Jan, at what point did the oops happen? Was it right after
> the device was detected, during removal,or some other time?
On startup, loaded by hotplug, I don't have any devices on that bus.
CONFIG_SCSI_SATA_VIA=m
>
> Can you put in some debugging printk's to see what values are in ap,
> ap->ops, and ap->ops->eng_timeout?
Where exactly? Patch would be appreciated.
Is that what you mean (hand edited)?
--- linux-2.6/drivers/scsi/libata-scsi.c.backup 2005-09-16 23:52:21.000000000
+0200
+++ linux-2.6/drivers/scsi/libata-scsi.c 2005-09-16 23:52:29.000000000
+0200
@@ -387,7 +387,9 @@
struct ata_port *ap;
DPRINTK("ENTER\n");
ap = (struct ata_port *) &host->hostdata[0];
+ printk("ap: %d %d %d\n", ap);
+ printk("ap->ops %d\n", ap->ops);
+ printk("ap->ops->eng_timeout %d\n", ap->ops->eng_timeout);
ap->ops->eng_timeout(ap);
I'll reboot with these changes, we'll see.
--
Jan
-
: send the line "unsubscribe linux-scsi" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
