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

Suresh Siddha
2008-06-24T23:23:39Z

On Mon, Jun 23, 2008 at 05:38:59AM -0700, Frans Pop wrote:
> On Sunday 15 June 2008, Siddha, Suresh B wrote:
> > Frans Pop wrote:
> > > On Saturday 14 June 2008, Rafael J. Wysocki 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
> > >
> > > Yes. See also: http://lkml.org/lkml/2008/6/13/159
> >
> > Frans, With or without pat, in the recent kernels (like 2.6.26-rc4/rc5
> > etc), ioremap() uses UC- and PCI mmap of /sys/devices/pci.../resource
> > (used by X) uses UC-
> >
> > And fb_mmap() also uses UC-.
> >
> > It's interesting that you don't see this artifact with "nopat".
> > Essentially with or with out pat enabled, we use the same memory
> > attributes. So depending on the MTRR setup (set by X server), effective
> > memory attribute across different mappings should be same (which is UC-
> > or WC with mtrr).
>
> Any progress on this issue? It's still there with -rc7, but I doubt that
> comes as a surprise.
>
> Has anyone tried to reproduce this? I would think that should be trivial.
>
> Just as a summary:
> - Intel 82945G/GZ graphics [8086:2772] (ICH7 based system)
> - FB_VESA=y, FRAMEBUFFER_CONSOLE=y
> - boot with vga=791
> - Log in to X and KDE; I do need to really log in there are no artifacts
> if I exit X from the kdm login dialog
> - artifacts show on logout
>
> I doubt it's KDE related or even related to my specific graphics card.
>
> It may well be related to what is or has been displayed on the display
> before logging out, so running some apps may make sense. Seems like I do
> see remnants of for example aptitude (Debian apt frontend) after I've run
> it in an X term (KDE's konsole).

FJP, We will try to reproduce this and getback. Your earlier responses did not
give many clues.

thanks,
suresh