[Intel-gfx] 2.6.31 -> 2.6.32 Sound and video regressions

[Emmanuel Benisty]

On Mon, Dec 7, 2009 at 8:32 AM, Jesse Barnes <jbarnes at virtuousgeek.org> wrote:
> On Sat, 05 Dec 2009 23:44:55 +0000
> Darren Salt <linux at 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