|Summary:||[965GM] PAT breaks xserver|
|Product:||xorg||Reporter:||Tobias Hain <tobias.hain>|
|Component:||Driver/intel||Assignee:||Wang Zhenyu <zhenyu.z.wang>|
|Status:||RESOLVED WORKSFORME||QA Contact:||Xorg Project Team <xorg-team>|
|i915 platform:||i915 features:|
Description Tobias Hain 2008-08-06 07:44:54 UTC
System: Dell XPS M1330 Distro: Ubuntu 8.04.1 Kernel: 18.104.22.168 (vanilla) xserver: X.Org X Server 22.214.171.1246 (1.5.0 RC 6) taken from Ubuntu intrepid xserver-xorg-core (2:126.96.36.1996-1ubuntu2) intel xorg video driver: . 2.4.99 git tip 2008/06/08 f91134795b545c8baebf218975b261c76a0e5873 . 2.3.2 taken from intrepid (2:2.3.2-2ubuntu3) description: . xserver won't start with git tip. Several flashes of distorted xserver images, but finally a black image. . only occours on PAT enabled kernel workaround: . use MTRR instead of PAT (Page Attribute Table) by adding "nopat" kernel option and git tip xserver runs fine . 2.3.2 release video driver will run even when PAT is enabled additional information: There are some interesting lines in X.log when using PAT and xserver fails: (WW) intel(0): ESR is 0x00000010, page table error (WW) intel(0): PGTBL_ER is 0x00000100, display B pte (WW) intel(0): Existing errors found in hardware state. [...] (II) intel(0): [drm] removed 1 reserved context for kernel (II) intel(0): [drm] unmapping 8192 bytes of SAREA 0xf8ecf000 at 0xb7f4a000 (II) intel(0): [drm] Closed DRM master. However I also have one X.log running PAT with this "page table error" on 2.3.2. In that case the xserver was running find - just having this warning. But in general 2.3.2 won't show these warnings. /proc/mtrr looks always like this once X is started (regardless of xserver and PAT): reg00: base=0x00000000 ( 0MB), size=2048MB: write-back, count=1 reg01: base=0x7f800000 (2040MB), size= 8MB: uncachable, count=1 reg02: base=0x7f700000 (2039MB), size= 1MB: uncachable, count=1 reg03: base=0xe0000000 (3584MB), size= 256MB: write-combining, count=1 However if xserver doesn't start and fails then the last line reg03 is not present.
Comment 1 Tobias Hain 2008-08-06 07:45:48 UTC
Created attachment 18156 [details] Xorg.log git tip video driver and PAT
Comment 2 Tobias Hain 2008-08-06 07:46:09 UTC
Created attachment 18157 [details] Xorg.log git tip video driver and MTRR
Comment 3 Tobias Hain 2008-08-06 07:46:39 UTC
Created attachment 18158 [details] Xorg.log 2.3.2 video driver and PAT
Comment 4 Tobias Hain 2008-08-07 01:38:06 UTC
I have seen this error meanwhile more often in X.log (WW) intel(0): ESR is 0x00000011, page table error (WW) intel(0): PGTBL_ER is 0x00040000, overlay tiling (WW) intel(0): Existing errors found in hardware state. It's a slight deviation compared to the error message above. However this one is taken from a gti tip video driver 2.4.99 and a 2.6.24 kernel with MTRR. And the X session that this error is taken from did work fine. Therefore I assume that this error message is not necessarily related to PAT. The driver seems to recover from that situation described by the warning.
Comment 5 Wang Zhenyu 2008-08-11 19:47:15 UTC
2.6.27-rc2 with PAT runs ok no my T61 with current video driver. I haven't tried .26 kernel yet.
Comment 6 Tobias Hain 2008-08-12 06:29:27 UTC
I just compiled 2.6.27-rc2 and it gives me the same result as 2.6.26. If I boot with PAT, then X server will flash a couple of times but no image. If I start with "nopat" kernel option everything works fine here. I diffed again the Xorg.0.log and the only real difference is this message which shows up when PAT is enabled: (II) intel(0): [drm] removed 1 reserved context for kernel (II) intel(0): [drm] unmapping 8192 bytes of SAREA 0xf8eed000 at 0xb7eea000 (II) intel(0): [drm] Closed DRM master. I frequently update intel drivers and if I have updates to this issue, I'll post them here. Meanwhile I consider this one not important since a workaround is known.
Comment 7 Michael Fu 2009-01-04 23:31:15 UTC
(In reply to comment #6) > I just compiled 2.6.27-rc2 and it gives me the same result as 2.6.26. > > If I boot with PAT, then X server will flash a couple of times but no image. If > I start with "nopat" kernel option everything works fine here. > > I diffed again the Xorg.0.log and the only real difference is this message > which shows up when PAT is enabled: > > (II) intel(0): [drm] removed 1 reserved context for kernel > (II) intel(0): [drm] unmapping 8192 bytes of SAREA 0xf8eed000 at 0xb7eea000 > (II) intel(0): [drm] Closed DRM master. > > I frequently update intel drivers and if I have updates to this issue, I'll > post them here. Meanwhile I consider this one not important since a workaround > is known. > Tobias, how much memory do you have in your T61? have any chance to try a newer ubuntu like 8.10? Zhenyu, What's your xserver version that can _not_ reproduce this bug?
Comment 8 Tobias Hain 2009-01-05 10:11:55 UTC
Actually I'm running a Dell XPS M1330 and not a T61 as stated in the first posting. It currently has 2GB of memory. This bug at some point of time disappeared. I'm now on Ubuntu 8.10 + vanilla 2.6.28 and can't tell at which point it started working again. Haven't bisected and there are too many component versions involved. Therefore I think it's best to close this bug. I don't mind reopening if I step on it again.
Comment 9 Wang Zhenyu 2009-01-05 17:27:03 UTC
ok, close now. If that appears again, we can open this and take a look again.