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

[Jens Axboe <axboe@suse.de>]

On Fri, Jun 02 2006, Chris Wright wrote:
> -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.

-- 
Jens Axboe