Bug 43012
| Summary: | i915 Modesetting - Offset Graphics - Panther Point Chipset with Sandy Bridge GPU | ||
|---|---|---|---|
| Product: | Drivers | Reporter: | Carl Richell (carl) |
| Component: | Video(DRI - Intel) | Assignee: | drivers_video-dri-intel (drivers_video-dri-intel) |
| Status: | CLOSED CODE_FIX | ||
| Severity: | normal | CC: | chris, daniel, florian |
| Priority: | P1 | ||
| Hardware: | All | ||
| OS: | Linux | ||
| Kernel Version: | 3.3.0-030300-generic #201203182135 | Subsystem: | |
| Regression: | Yes | Bisected commit-id: | |
| Attachments: |
Picture of offset desktop
dmesg boot through suspend and resume intel_reg_dumper broken state intel_reg_dumper working state xrandr broken state xrandr working state Sanitize debugging state leftover by the BIOS |
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Description
Carl Richell
2012-03-30 01:37:41 UTC
Created attachment 72747 [details]
Picture of offset desktop
Ok, can you please boot with drm.debug=0xe added to your kernel cmdline, got through suspend/resume (to fix your screen) and then attach your full dmesg (since boot). Please make sure that you have printk timestamps enabled. Then also grab the latest intel-gpu-tools (1.2) and attach the complete output of intel_reg_dumper once for the broken state (right after boot) and once for the working state (after resume). Also please attach the output of xrandr --verbose for both cases. Please attach these files individually as text/plain - much easier to handle than a tar.bz. Created attachment 72757 [details]
dmesg boot through suspend and resume
Created attachment 72758 [details]
intel_reg_dumper broken state
Created attachment 72759 [details]
intel_reg_dumper working state
Created attachment 72760 [details]
xrandr broken state
Created attachment 72761 [details]
xrandr working state
Created attachment 72762 [details]
Sanitize debugging state leftover by the BIOS
Chris, your patch works beautifully. From your comments, this sounds like a BIOS bug. Please clarify what should be fixed in the BIOS and I will relay the information. We should be able to fix the BIOS before these particular systems actually reach the wild. Hmm, Panther Point. If you have the Intel BIOS, I think we have notified the team already. The part in question are bits 3<<27 in the PIPEACONF/PIPEBCONF registers which modify when the display engine starts reading from the pipe following the vblank and are earmarked for debugging use only. The BIOS is leaving those bits turned on. Excellent, thank you Chris. commit f47166d2b0001fcb752b40c5a2d4db986dfbea6 Author: Chris Wilson <chris@chris-wilson.co.uk> Date: Thu Mar 22 15:00:50 2012 +0000 drm/i915: Sanitize BIOS debugging bits from PIPECONF Quoting the BSpec from time immemorial: PIPEACONF, bits 28:27: Frame Start Delay (Debug) Used to delay the frame start signal that is sent to the display planes. Care must be taken to insure that there are enough lines during VBLANK to support this setting. An instance of the BIOS leaving these bits set was found in the wild, where it caused our modesetting to go all squiffy and skewiff. Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=47271 Reported-and-tested-by: Eva Wang <evawang@linpus.com> Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=43012 Reported-and-tested-by: Carl Richell <carl@system76.com> Cc: stable@kernel.org Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> A patch referencing this bug report has been merged in Linux v3.4-rc2: commit f47166d2b0001fcb752b40c5a2d4db986dfbea68 Author: Chris Wilson <chris@chris-wilson.co.uk> Date: Thu Mar 22 15:00:50 2012 +0000 drm/i915: Sanitize BIOS debugging bits from PIPECONF A patch referencing a commit referencing this bug report has been merged in Linux v3.5-rc1: commit a9dcf84b14ef4e9a609910367576995e6f32f3dc Author: Daniel Vetter <daniel.vetter@ffwll.ch> Date: Sun May 13 22:29:25 2012 +0200 drm/i915: don't clobber the pipe param in sanitize_modesetting |