Bug#432435: Regression: 1600x1200 output shows artifacts

[Brice Goglin <Brice.Goglin@ens-lyon.org>]

tags 432425 +patch
thank you



Dylan Thurston wrote:
> The current version of xserver-xorg-video-intel shows artifacts when
> displaying on my external monitor, connected with a DVI output: I see
> a grid of black dots, and a shimmering pattern.  Lower resolutions
> work fine.
>
> This bug also occurs with 2.0.0-6.  Version 2.0.0-5 works fine.  I've
> also attached the Xorg log from the working version, 2.0.0-5.
>   

Hi,

Thanks for testing multiple versions, it helps a lot since the changes
between -5 and -6 are pretty small. There's a least one small bug that
have been reported (by me) in this changes. It regards large resolution
on i9xx chipsets and is not fixed upstream so far. To workaround it, you
may either revert commit 1e2e301348b4168aeed38b3fdc6b0e43d5678a86, or
just apply the attached patch. Please let me know whether it helps.

Brice

diff --git a/src/i830_display.c b/src/i830_display.c
index ebde525..28be1ab 100644
--- a/src/i830_display.c
+++ b/src/i830_display.c
@@ -1055,12 +1055,14 @@ i830_crtc_mode_set(xf86CrtcPtr crtc, DisplayModePtr mode,
     OUTREG(vtot_reg, (adjusted_mode->CrtcVDisplay - 1) |
 	((adjusted_mode->CrtcVTotal - 1) << 16));
     
+#if 0
     /*
      * Give us some border at the bottom for load detection
      */
     adjusted_mode->CrtcVBlankStart = adjusted_mode->CrtcVSyncStart;
     if (adjusted_mode->CrtcVBlankEnd - adjusted_mode->CrtcVBlankStart < 3)
 	adjusted_mode->CrtcVBlankStart = adjusted_mode->CrtcVBlankEnd - 3;
+#endif
     
     OUTREG(vblank_reg, (adjusted_mode->CrtcVBlankStart - 1) |
 	((adjusted_mode->CrtcVBlankEnd - 1) << 16));