[Intel-gfx] Screen flickering with kernel 2.6.33-rc3

[Jesse Barnes]

On Thu, 7 Jan 2010 00:24:16 +0100
Hanno Böck <hanno at hboeck.de> wrote:

> Am Mittwoch 06 Januar 2010 schrieb Jesse Barnes:
> > On Wed, 6 Jan 2010 23:36:35 +0100
> > 
> > Hanno Böck <hanno at hboeck.de> wrote:
> > > Hi,
> > >
> > > I switched to kernel 2.6.33-rc3 (due to reasons unrelated to
> > > graphics), and it causes my monitor to flicker from time to time
> > > (frequency is something about some minutes).
> > >
> > > This didn't happen with 2.6.32.2. It happens with both
> > > xf86-video-intel-2.9.1 and 2.10.0, mesa is at 7.7 and xorg-server
> > > at 1.7.3.902. (Gentoo Linux)
> > >
> > > Any ideas? There's nothing suspicious in Xorg.0.log or dmesg.
> > 
> > Does the flickering still occur if you load the i915 module with
> > powersave=0?
> 
> No. Tried this for about half an hour and saw no more flickering.

So it's either FBC related or LVDS downclock related since self-refresh
is unconditional now.  Does this patch also make the flicker go away?

Jesse

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 9187a17..0ab1bef 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -3806,7 +3806,7 @@ static void intel_increase_pllclock(struct drm_crtc *crtc, bool schedule)
 	if (IS_IRONLAKE(dev))
 		return;
 
-	if (!dev_priv->lvds_downclock_avail)
+	if (!dev_priv->lvds_downclock_avail || 1)
 		return;
 
 	if (!HAS_PIPE_CXSR(dev) && (dpll & DISPLAY_RATE_SELECT_FPA1)) {
@@ -3845,7 +3845,7 @@ static void intel_decrease_pllclock(struct drm_crtc *crtc)
 	if (IS_IRONLAKE(dev))
 		return;
 
-	if (!dev_priv->lvds_downclock_avail)
+	if (!dev_priv->lvds_downclock_avail || 1)
 		return;
 
 	/*