Re: [patch 29/30] sata_nv: don't read shadow registers when in ADMA mode

[Alistair John Strachan]

On Friday 09 March 2007 14:27, you wrote:
> Jeff Garzik wrote:
> > akpm@xxxxxxxxxxxxxxxxxxxx wrote:
> >> From: Robert Hancock <hancockr@xxxxxxx>
> >>
> >> Reading from the ATA shadow registers while we are in ADMA mode may
> >> cause undefined behavior.  Don't read the ATA status register when
> >> completing commands for this reason, it shouldn't be needed as the
> >> controller will notify us if the command failed.  Also, don't allow
> >> commands with result taskfile requested to execute in ADMA mode, since
> >> that requires accessing the shadow registers.  We also still need to
> >> override tf_read since libata
> >> will read the result taskfile on a command failure, and we need to go
> >> into
> >> port register mode before allowing this.
> >>
> >> Signed-off-by: Robert Hancock <hancockr@xxxxxxx>
> >> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> >> ---
> >>
> >>  drivers/ata/sata_nv.c |   33 ++++++++++++++++++++-------------
> >>  1 file changed, 20 insertions(+), 13 deletions(-)
> >
> > Robert, do you think this should be pushed into #upstream-fixes
> > (2.6.21-rc)?
> >
> > I lean towards "yes", since it is a needed-by-hardware fix, but I also
> > am interested in testing feedback since it is so late in the 2.6.21-rc
> > game.
>
> I would lean toward that as well, but it would be good to get some
> testing from some sata_nv ADMA users to make sure it doesn't do anything
> funny for them..

Since I've been a bit of a problem case this time, I'd be happy to test it.

Can I assume that I can apply the patch you sent to Jeff "[PATCH] sata_nv: 
revert use of notifiers for now", and apply this one, to -rc3, and then be 
able to usefully test?

-- 
Cheers,
Alistair.

Final year Computer Science undergraduate.
1F2 55 South Clerk Street, Edinburgh, UK.
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