Bug 28626 - Oops: kernel NULL pointer dereference in nouveau_connector_get_modes
Summary: Oops: kernel NULL pointer dereference in nouveau_connector_get_modes
Status: RESOLVED FIXED
Alias: None
Product: xorg
Classification: Unclassified
Component: Driver/nouveau (show other bugs)
Version: git
Hardware: x86-64 (AMD64) Linux (All)
: medium major
Assignee: Nouveau Project
QA Contact: Xorg Project Team
URL:
Whiteboard:
Keywords:
Depends on:
Blocks:
 
Reported: 2010-06-20 09:26 UTC by Albert Damen
Modified: 2010-06-21 03:43 UTC (History)
0 users

See Also:
i915 platform:
i915 features:

Attachments
dmesg with the oops (68.30 KB, text/plain)
2010-06-20 09:26 UTC, Albert Damen 		no flags Details
Suggested patch (849 bytes, patch)
2010-06-20 09:29 UTC, Albert Damen 		no flags Details | Splinter Review
View All

Description Albert Damen 2010-06-20 09:26:57 UTC 
Created attachment 36380 [details]
dmesg with the oops

Booting with nouveau/linux-2.6 from git results in a kernel oops:
[    3.817681] BUG: unable to handle kernel NULL pointer dereference at 0000000000000060
[    3.818051] IP: [<ffffffffa01128b0>] nouveau_connector_get_modes+0x180/0x410 [nouveau]
Please see attached dmesg for the full oops.

System environment:
-- chipset: intel PM965 + G86 [GeForce 8400M GT]
-- system architecture: 64-bit
-- xf86-video-nouveau: git, db98ad2363 (20 June)
-- xserver: 1.7.5
-- libdrm: 2.4.20
-- kernel: 2.6.34 + nouveau/linux from git: 48f4092e87
-- Machine: laptop, Sony Vaio FZ21-M
-- Display connector: LVDS (1280x800) + HDMI (1680x1050)

Reverting commit "drm/nouveau: move LVDS detection back to connector detect() time" solved the oops.
Further debugging showed nv_encoder was NULL in nouveau_connector_get_modes.
Attached patch solves the problem for me.
Comment 1 Albert Damen 2010-06-20 09:29:17 UTC 
Created attachment 36381 [details] [review]
Suggested patch
Comment 2 Francisco Jerez 2010-06-21 03:43:19 UTC 
(In reply to comment #0)
> Reverting commit "drm/nouveau: move LVDS detection back to connector detect()
> time" solved the oops.
> Further debugging showed nv_encoder was NULL in nouveau_connector_get_modes.
> Attached patch solves the problem for me.

Thanks, that's the right thing to do, pushed.

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