Comment 29 for bug 661546

I'm running into the same issue on Natty. This is on a MacBook 2,1 with an external monitor. Intel 945GM chipset. It appears to be related to the framebuffer size. The laptop panel works fine alone, as does an external monitor at 1920x1080 alone.

However, if I enable both displays at full resolution, then I get the "Failed to set tiling on frontbuffer" error message in Xorg.0.log, and compositing is *very slow*. If I reduce the resolution on both monitors, then I can get it working correctly again.

Here's an error log from the failed case:

[ 8845.595] (II) intel(0): EDID vendor "APP", prod id 40030
[ 8845.595] (II) intel(0): Printing DDC gathered Modelines:
[ 8845.595] (II) intel(0): Modeline "1280x800"x0.0 71.00 1280 1328 1360 1440 800 803 809 823 -hsync -vsync (49.3 kHz)
[ 8876.129] (II) intel(0): EDID vendor "APP", prod id 40030
[ 8876.129] (II) intel(0): Printing DDC gathered Modelines:
[ 8876.129] (II) intel(0): Modeline "1280x800"x0.0 71.00 1280 1328 1360 1440 800 803 809 823 -hsync -vsync (49.3 kHz)
[ 8876.332] (WW) intel(0): Failed to set tiling on frontbuffer.
[ 8876.332] (II) intel(0): Allocated new frame buffer 2112x800 stride 8448, untiled

And here is the log with a resolution small enough that it works:

[ 8945.829] (II) intel(0): EDID vendor "APP", prod id 40030
[ 8945.829] (II) intel(0): Printing DDC gathered Modelines:
[ 8945.830] (II) intel(0): Modeline "1280x800"x0.0 71.00 1280 1328 1360 1440 800 803 809 823 -hsync -vsync (49.3 kHz)
[ 8946.009] (II) intel(0): EDID vendor "APP", prod id 40030
[ 8946.009] (II) intel(0): Printing DDC gathered Modelines:
[ 8946.009] (II) intel(0): Modeline "1280x800"x0.0 71.00 1280 1328 1360 1440 800 803 809 823 -hsync -vsync (49.3 kHz)
[ 8946.230] (II) intel(0): Allocated new frame buffer 1792x864 stride 8192, tiled

g.