Re: [PATCH 07/11] the latest consensus libata resume fix

[Marcel Holtmann <marcel@holtmann.org>]

Hi Jens,

> > -stable review patch.  If anyone has any objections, please let us know.
> > ------------------
> > 
> > From: Mark Lord <liml@rtr.ca>
> > 
> > Okay, just to sum things up.
> > 
> > This forces libata to wait for up to 2 seconds for BUSY|DRQ to clear
> > on resume before continuing.
> > 
> > [jgarzik adds...]  During testing we never saw DRQ asserted, but
> > nonetheless (a) this works and (b) testing for DRQ won't hurt.
> > 
> > Signed-off-by:  Mark Lord <liml@rtr.ca>
> > Acked-by: Jens Axboe <axboe@suse.de>
> > Signed-off-by: Jeff Garzik <jeff@garzik.org>
> > Signed-off-by: Chris Wright <chrisw@sous-sol.org>
> > Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
> > ---
> > 
> >  drivers/scsi/libata-core.c |    1 +
> >  1 file changed, 1 insertion(+)
> > 
> > --- linux-2.6.16.19.orig/drivers/scsi/libata-core.c
> > +++ linux-2.6.16.19/drivers/scsi/libata-core.c
> > @@ -4293,6 +4293,7 @@ static int ata_start_drive(struct ata_po
> >  int ata_device_resume(struct ata_port *ap, struct ata_device *dev)
> >  {
> >  	if (ap->flags & ATA_FLAG_SUSPENDED) {
> > +		ata_busy_wait(ap, ATA_BUSY | ATA_DRQ, 200000);
> >  		ap->flags &= ~ATA_FLAG_SUSPENDED;
> >  		ata_set_mode(ap);
> >  	}
> 
> I'm not against the patch as such, but last I checked 2.6.16 actually
> worked ok. The timer fixes in 2.6.17-rc is what apparently got the
> resume breaking.
> 
> So unless there's a bug report on 2.6.16.x for this, then it's a little
> against the -stable rules to add it.

I had problems with resume on my IBM X41 since I got it (something
around 2.6.15) and only this patch made it work again.

Because of the SDHCI stuff I always used the latest kernel and thus I
wasn't sure if there actually was a problem or not. So I tested a plain
2.6.16 with and without this patch. The plain 2.6.16 doesn't resume on
my IBM X41 laptop. If I apply this patch, the resume works perfect.

Regards

Marcel