lkml.org 
[lkml]   [2005]   [Sep]   [24]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] updated version of Jens' SATA suspend-to-ram patch
On Fri, Sep 23 2005, Jeff Garzik wrote:
> >--- linux-2.6.13/drivers/scsi/libata-core.c~ 2005-09-01
> >12:22:19.000000000 +0200
> >+++ linux-2.6.13/drivers/scsi/libata-core.c 2005-09-01
> >12:24:38.000000000 +0200
> >@@ -3738,8 +3738,8 @@
> > unsigned long flags;
> > int rc;
> >
> >- qc = ata_qc_new_init(ap, dev);
> >- BUG_ON(qc == NULL);
> >+ while ((qc = ata_qc_new_init(ap, dev)) == NULL)
> >+ msleep(10);
> >
> > qc->tf.command = cmd;
> > qc->tf.flags |= ATA_TFLAG_DEVICE;
>
> Worried now!
>
> If this patch is needed, something VERY VERY WRONG is going on. This
> patch indicates that the queueing state machine has been violated, and
> something is trying to IGNORE the command synchronization :(

I haven't diagnosed this further and it only ever happened in the SUSE
kernel to my knowledge (no one has reported it to me for the vanilla
kernels + suspend patch).

So lets just keep this patch out of the equation for now, it could be
that other SUSE patches broke something in this area :/

> Further, you cannot always assume that msleep() is valid in that
> context. It should be the caller that waits (libata suspend code), not
> ata_do_simple_cmd() itself.

ata_do_simple_cmd() always blocks anyways, so I don't see the point.
Perhaps rename the function to ata_execute_and_wait_simple_cmd().

--
Jens Axboe

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-09-24 09:09    [from the cache]
©2003-2014 Jasper Spaans. Advertise on this site