Bug 29057

Does it break before this patch if you change the aspect ratio as well?  If so, our aspect handling is the real bug, this patch just exposed it more readily.

You are right. It break before this patch if I change the aspect ratio from 'Full' to 'Full Aspect'. When scaling mode is 'Full Aspect', change resolution to 800x600, screen get messed up(after runnig ut2004, resolution changed from 1024x600 to 800x600, so the problem occurs).

The regression is:

commit 734b4157b367d66405f7dab80085d17c9c8dd3b5
Author: Krzysztof Halasa <khc@pm.waw.pl>
Date:   Tue May 25 18:41:46 2010 +0200

    drm/i915: Add support for interlaced display.
    
    This doesn't change the clock limits (minimums), i.e. it won't make it
    output 720x576 PAL nor 720x480 NTSC, but it will work with modes like
    1080i etc. (including GLX and textured Xvideo, not sure about the
    overlay).
    
    Tested on i915 + analog VGA, it would be worth checking if newer chips
    (and which ones) still support interlaced mode.
    
    Signed-off-by: Krzysztof Halasa <khc@pm.waw.pl>
    Signed-off-by: Eric Anholt <eric@anholt.net>

in particular the stray:

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 36afe94..4c7c151 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -2354,6 +2354,8 @@ static bool intel_crtc_mode_fixup(struct drm_crtc *crtc,
                if (mode->clock * 3 > 27000 * 4)
                        return MODE_CLOCK_HIGH;
        }
+
+       drm_mode_set_crtcinfo(adjusted_mode, 0);
        return true;
 }

Created attachment 37147 [details] [review]
Fix panel fitting regression.

It works fine with the patch. Thanks.

fangxuan, do you mind replying to 1279367168-24108-1-git-send-email-chris@chris-wilson.co.uk on intel-gfx@lists.freedesktop.org with your tested-by? Thanks.

Thanks Chris.

commit 0cc4d4300c28d5c3fc73e5ec91bfd4b0c2c744af
Author: Chris Wilson <chris@chris-wilson.co.uk>
Date:   Sat Jul 17 12:43:20 2010 +0100

    drm/i915: Fix panel fitting regression since 734b4157
    
    The crtc mode fixup is run after the encoders adjust the mode to fit on
    their output, so don't reset the mode!
    
    Fixes:
    
      Bug 29057 - display corruption under 800x600 on netbook
                  (1024x600) with 'Full Aspect' scaling
      https://bugs.freedesktop.org/show_bug.cgi?id=29057
    
    Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
    Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
    Tested-by: Xun Fang <xunx.fang@intel.com>
    Signed-off-by: Eric Anholt <eric@anholt.net>

Applied to anholt/for-linus [2.6.35]

Mark it as verified.

Closing old verified+fixed.