Re: [Bug 10843] Display artifacts on XOrg logout with PAT kernel and VESA framebuffer

Frans Pop
2008-06-15T23:02:25Z

On Sunday 15 June 2008, Siddha, Suresh B wrote:
> > Bug-Entry : http://bugzilla.kernel.org/show_bug.cgi?id=10843
> > Subject : Display artifacts on XOrg logout with PAT kernel
> > and VESA framebuffer
> > Submitter : Frans Pop <elendil@planet.nl>
> > Date : 2008-05-31 14:04 (15 days old)
> > References : http://lkml.org/lkml/2008/6/7/206
>
> Can you also check, if there is any impact with kernel boot param for
> vesafb "mtrr:3"?

Hello Suresh. Thanks for responding.

I've done 4 successive boots with the boot parameters as shown below.
Each boot was basically: set correct parameters in grub -> login to KDE
-> reboot and check for artifacts.

1) (none) --> clean
2) vga=791 --> artifacts
3) vga=791 nopat --> clean
4) vga=791 video=vesafb:mtrr:3 --> artifacts

So the mtrr option did not help (if I passed it correctly; the double ":"
is somewhat non-intuitive). The kernel log also does not show any
difference I can see in the last boot, but I don't know if the mtrr option
is supposed to show up in any way.

>From the kernel log for each boot:
1) x86 PAT enabled: cpu 0, old 0x7040600070406, new 0x7010600070106
Console: colour VGA+ 80x25
console [tty0] enabled

2) x86 PAT enabled: cpu 0, old 0x7040600070406, new 0x7010600070106
Console: colour dummy device 80x25
console [tty0] enabled
vesafb: framebuffer at 0x80000000, mapped to 0xffffc20000900000, using 3072k, total 7872k
vesafb: mode is 1024x768x16, linelength=2048, pages=4
vesafb: scrolling: redraw
vesafb: Truecolor: size=0:5:6:5, shift=0:11:5:0
Console: switching to colour frame buffer device 128x48
fb0: VESA VGA frame buffer device

3) PAT support disabled
Console: colour dummy device 80x25
console [tty0] enabled
vesafb: framebuffer at 0x80000000, mapped to 0xffffc20000900000, using 3072k, total 7872k
vesafb: mode is 1024x768x16, linelength=2048, pages=4
vesafb: scrolling: redraw
vesafb: Truecolor: size=0:5:6:5, shift=0:11:5:0
Console: switching to colour frame buffer device 128x48
fb0: VESA VGA frame buffer device

4) x86 PAT enabled: cpu 0, old 0x7040600070406, new 0x7010600070106
Console: colour dummy device 80x25
console [tty0] enabled
vesafb: framebuffer at 0x80000000, mapped to 0xffffc20000900000, using 3072k, total 7872k
vesafb: mode is 1024x768x16, linelength=2048, pages=4
vesafb: scrolling: redraw
vesafb: Truecolor: size=0:5:6:5, shift=0:11:5:0
Console: switching to colour frame buffer device 128x48
fb0: VESA VGA frame buffer device

Hope that helps. If you need any additional information, please ask.

Cheers,
FJP