Bug 101001

Summary: [BISECTED] Regression: drm/i915 crashes on boot (Broadwell)
Product: Drivers Reporter: Lukáš Hrázký (lukkash)
Component: Video(DRI - Intel)Assignee: intel-gfx-bugs (intel-gfx-bugs)
Status: RESOLVED INVALID    
Severity: normal CC: intel-gfx-bugs
Priority: P1    
Hardware: Intel   
OS: Linux   
Kernel Version: 4.1.1 Subsystem:
Regression: Yes Bisected commit-id:
Attachments: picture of the crash of the offending commit while bisecting
picture of the crash of the 4.1.1 version
.config

Description Lukáš Hrázký 2015-07-05 19:21:11 UTC 
Created attachment 181911 [details]
picture of the crash of the offending commit while bisecting

My Thinkpad T450s (i5-5300U) won't boot with kernel version 4.1.1. 4.0.5 boots fine (Although I've seen some weird failures of the i915 driver in syslog from time to time. I can try to look them up and provide them on request.).

I've bisected the kernel to find the offending commit:

commit 678d96fbb3b5995a2fdff2bca5e1ab4a40b7e968
Author: Ben Widawsky <benjamin.widawsky@intel.com>
Date:   Mon Mar 16 16:00:56 2015 +0000

    drm/i915: Track GEN6 page table usage


The traces printed to the console vary a lot. Sometimes I'd just get a blinking cursor. Attached are 2 photos, the console1.jpg I got when I found the offending commit while bisecting, the console2.jpg is from the 4.1.1 version.

My .config is attached. I'm running an up to date 'unstable' Gentoo system and compile everything into the kernel - no modules.
Comment 1 Lukáš Hrázký 2015-07-05 19:22:26 UTC 
Created attachment 181921 [details]
picture of the crash of the 4.1.1 version
Comment 2 Lukáš Hrázký 2015-07-05 19:23:31 UTC 
Created attachment 181931 [details]
.config
Comment 3 Lukáš Hrázký 2015-07-11 12:51:44 UTC 
Still present in 4.1.2.
Comment 4 Jani Nikula 2015-10-07 11:51:19 UTC 
Neither of the crashes seem to be related to drm/i915, really, which also calls the bisect result into question.

If the problem persists with latest kernels, and you think the bisect result is right, please file a bug at the freedesktop.org bugzilla [1], referencing this bug. Thank you.

[1] https://bugs.freedesktop.org/enter_bug.cgi?product=DRI&component=DRM/Intel