Re: [PATCH 1/2] i915: Remove pipe A force quirk for 855GM and 845G

Chris Wilson
2011-03-21T07:38:34Z

On Sun, 20 Mar 2011 23:07:04 +0000, Ben Hutchings <ben@decadent.org.uk> wrote:
> Applying this quirk to the 855GM in all systems causes regressions
> (Debian bugs #493096, #619019). Instead, apply the quirk to specific
> models as listed in the old X driver.
>
> I don't see any explanation for this quirk being applied to the 845G,
> except perhaps that VT switching used to hang if pipe A was turned
> off. However, that seems to be a problem only when using UMS. So
> remove the quirk for the 845G as well.

The quirk should only be required for 830M due to the numerous instances
where a unit on the second pipe is actually wired into the clock on the
first pipe. (And so it is easiest to keep the first pipe active at all
times.)

I'd prefer the quirk table to disappear and simply be replaced by
IS_830M(). However, that requires testing and so should only be done
piecemeal. And leaves some doubt as to why the other machines were in the
quirk table in the first place.

Can you please repost each of these removals as a separate patch and lets
try and get a tested-by for each one? (Make sure the tester includes the
model name for his machine so we can double check the veracity of the
change.)