Intel SATA ICH5/5R 6300ESB support patches

[Søren Schmidt]

Doug Ambrisko wrote:
> Here are some patches to deal with SATA devices causing errors and 
> resulting in wedged systems.  Deals with drives removed/powered down,
> drives powered up or plugged in and media errors.  We need to
> read the SATA registers and twiddle the port enable on device 
> departures.  If we don't then the ata code execution will result in
> a lock-up.
> 
> I put in a patch for geom for bio_taskqueue_remove.  Since ata code
> schedules bio_task it need to be cancelled when we abort and call
> biodone.  If we don't cancel this task then when the task is 
> run later we get a double free in UMA since we have cleaned up
> twice and called biodone twice for the same request.  It seems
> like in biodone we should clean up tasks there.  Suggestions
> appreciated.  This band-aids it for:
>      1)	dd if=/dev/ad2 of=/dev/null
>      2)	then power down the drive.
> 
> There are other issues on media recovery that I've hit but
> I'm going to do that separate to this HW support.  Promise
> patches to deal with SATA issues should be coming soon.
> 
> These are based on my -stable patches but are enhanced a little to
> deal with some other cases.
> 
> This should make -current systems more stable with SATA drives when
> something goes wrong with them.
> 
> I'd like to commit them to -current after a review.

Well, looks promising, but unfortunatly they collide with the WIP I have 
here in the lab, so I'd appreciate if you would not commit it right now.
I'll look into getting the confilicting areas merged into what I have 
here, then have you test it on the ICH5 as I dont have any of those 
around...

-- 
-Søren