Messages in this thread | | | Date | Sun, 14 Sep 2008 15:25:20 +0200 | From | Ingo Molnar <> | Subject | Re: [Bug 10843] Display artifacts on XOrg logout with PAT kernel and VESA framebuffer |
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* Frans Pop <elendil@planet.nl> wrote:
> On Saturday 13 September 2008, Pallipadi, Venkatesh wrote: > > >We have too many entires in PAT list due to RAM pages being marked > > >UC by drivers. Unfortunately, there are no quick fixes that can fix > > >this for 2.6.27. However, we are aware of the problem here and > > >working on a more complete fix for this. We should have the patch > > >for it soon. > > > > Can you try the patch here > > http://www.ussg.iu.edu/hypermail/linux/kernel/0809.1/2074.html > > And report back whether that resolves the issue. > > Yes, that solves the issue. The display is now free of artifacts > again, both on logout and when I switch users in X. The > pat_memtype_list looks a lot more sane too (see attachment). > > So it _was_ a regression caused by pat itself after all, and not the > result of incorrect memory handling in the framebuffer code. Could you > take over the bug report #10843 in bugzilla (it is currently assigned > to the framebuffer people) and ensure it gets closed once the patch > gets accepted in Linus' tree?
ok, since those patches are only supposed to improve performance, it would be nice to know why this fixes the display artifacts. They were a rather long-living bug and we'd like to avoid such bug patterns in the future.
or is it the timing effect? Too slow programming of the GX chip causes artifacts? (but i think this is not very likely)
Ingo
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