Re: [git pull] drm intel only fixes

[Jesse Barnes <jbarnes@virtuousgeek.org>]

On Wed, 12 Jan 2011 11:22:58 -0800
Linus Torvalds <torvalds@linux-foundation.org> wrote:

> On Tue, Jan 11, 2011 at 10:03 PM, Dave Airlie <airlied@linux.ie> wrote:
> >
> > I'm stuck at home with just my i5 laptop due to the office being shut due
> > to the ongoing floods. But I've booted and ran this for a few hours and it
> > seems to be better than the current tree. It contains a couple of patches
> > to fix DMAR interaction issues I see on this laptop on top of Chris's
> > pull.
> 
> Hmm. I'm not seeing the screensaver issue any more, but there's
> something wrong with video. At least the TED ones (I'm not seeing it
> on a youtube video i tried). See for example
> 
>   http://www.ted.com/talks/lang/eng/david_gallo_shows_underwater_astonishments.html
> 
> and when there is fast movement in the video (like when the octopus is
> spooked), I get these odd lines of noise.
> 
> In fact, while I noticed the lines in the video itself, it's actually
> most repeatably noticeable in the buttons underneath while the video
> is playing: make your mouse go back-and-forth between the "rate" and
> "share" buttons, and they get corrupted (and it also corrupts the
> progress bar).
> 
> It looks a bit like the noise you get with insufficient memory
> bandwidth, but I doubt that's the case here. Perhaps just some
> motion-comp problem?
> 
> Any ideas?

Since I doubt we're actually offloading to our video decode kernels for
Flash video on your machine, it could very well be a memory bw issue.
Can you try this small patch to see if one of the low power watermarks
is giving you trouble (note: cut & pasted)?

It could also be the normal power watermarks though too; you could just
make plane-wm and cursor_wm higher to test that.

-- 
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 9ef5578..4e8af4d 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -3600,6 +3600,8 @@ static void ironlake_update_wm(struct drm_device *dev,
        if (enabled != 1)
                return;
 
+       return;
+
        clock = planea_clock ? planea_clock : planeb_clock;
 
        /* WM1 */