Re: 2.6.31 -> 2.6.32 Sound and video regressions

[Emmanuel Benisty <benisty.e@gmail.com>]

On Fri, Dec 18, 2009 at 2:05 AM, Jesse Barnes <jbarnes@virtuousgeek.org> wrote:
> On Thu, 10 Dec 2009 09:54:22 -0800
> Jesse Barnes <jbarnes@virtuousgeek.org> wrote:
>
>> On Tue, 8 Dec 2009 20:20:07 +0700
>> Emmanuel Benisty <benisty.e@gmail.com> wrote:
>>
>> > On Mon, Dec 7, 2009 at 8:38 PM, Emmanuel Benisty
>> > <benisty.e@gmail.com> wrote:
>> > > On Mon, Dec 7, 2009 at 10:52 AM, Emmanuel Benisty
>> > > <benisty.e@gmail.com> wrote:
>> > >> On Mon, Dec 7, 2009 at 8:32 AM, Jesse Barnes
>> > >> <jbarnes@virtuousgeek.org> wrote:
>> > >>> On Sat, 05 Dec 2009 23:44:55 +0000
>> > >>> Darren Salt <linux@youmustbejoking.demon.co.uk> wrote:
>> > >>>
>> > >>>> I demand that Andy Lutomirski may or may not have written...
>> > >>>>
>> > >>>> > Emmanuel Benisty wrote:
>> > >>>> [snip]
>> > >>>> >> I just wanted to report 2 regressions I am having now with
>> > >>>> >> 2.6.32. Video
>> > >>>> >> Screen is flickering/glitching like crazy in X. It happens
>> > >>>> >> whether randomly or when conky is refreshed, when the mouse
>> > >>>> >> cursor moves and like hell when a page is loading in the
>> > >>>> >> browser. Not so easy to describe this issue.
>> > >>>> [snip]
>> > >>>>
>> > >>>> > That sounds like FIFO underruns, which (I think) were
>> > >>>> > introduced when self-refresh was enabled but should have been
>> > >>>> > fixed. I personally have no clue how to fix them, but if you
>> > >>>> > told the Intel people what kind of chip you have (lspci
>> > >>>> > output), they can probably fix it.
>> > >>>>
>> > >>>> It also sounds like what I'm seeing on my EeePC 901. It only
>> > >>>> happens after resume, which makes STR a little less than
>> > >>>> useful; the display will, sooner or later, show a single
>> > >>>> colour (which is, presumably, the result of a display engine
>> > >>>> hang, as described in the comment immediately before
>> > >>>> intel_calculate_wm) and, seemingly, be stuck like that until
>> > >>>> power-off or reboot.
>> > >>>>
>> > >>>> Whether it *is* the same problem, I couldn't say.
>> > >>>>
>> > >>>> Needless to say, this problem goes away if I disable KMS.
>> > >>>
>> > >>> Arg, there are a few reports of this now, but I haven't been
>> > >>> able to reproduce it.  I'll try harder...  (FYI the upstream
>> > >>> bugs.freedesktop.org # for it is 24314).
>> > >>
>> > >> It *seems* that we are facing two different issues here (I don't
>> > >> even use S2R and the problem is there since the very first second
>> > >> I start X). Anyway, I have bisected the problem on my box, it
>> > >> turns out to be this one:
>> > >>
>> > >> drm/i915: Fix render reclock availability detection
>> > >>
>> > >> http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=181a5336d6cc836f05507410d66988c483ad0154
>> > >>
>> > > So, I have reverted this commit and rebuilt 2.6.32. It completely
>> > > solved the issue described in my first post.
>> > >
>> >
>> > just FTR, it looks like I'm not alone:
>> > http://forums.gentoo.org/viewtopic-p-6087556.html#6087556
>>
>> Great, thanks for narrowing it down.  I'll see if I can come up with a
>> fix.
>
> Can you give this a try?
>
> --
> Jesse Barnes, Intel Open Source Technology Center
>
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_d
> index 279dc96..5bde801 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -3808,6 +3808,8 @@ void intel_decrease_renderclock(struct drm_device *dev)
>  {
>        drm_i915_private_t *dev_priv = dev->dev_private;
>
> +       return;
> +
>        if (IS_IRONLAKE(dev))
>                return;
>
>

Thanks a lot Jesse, I have tried your bugzilla patch. Anyone
interested, it's here:
http://bugzilla.kernel.org/show_bug.cgi?id=14781