[Bug 73901] New: Kernel crash after modprobe radeon runpm=1

bugzilla-daemon
2014-04-12T18:44:22Z

Bug ID: 73901
Summary: Kernel crash after modprobe radeon runpm=1
Product: Drivers
Version: 2.5
Kernel Version: 3.14
Hardware: x86-64
OS: Linux
Tree: Mainline
Status: NEW
Severity: high
Priority: P1
Component: Video(DRI - non Intel)
Assignee: drivers_video-dri@kernel-bugs.osdl.org
Reporter: pali.rohar@gmail.com
Regression: No

After modprobing radeon driver with runpm=1 notebook display panel output is
immediatelly black (probably turned off) and after one or two seconds kernel
freeze/crash (sysrq not working too). I was able to dump & sync syslog kernel
output before freeze (called sync command in infinite loop on background). See
attachment where is log from syslog daemon after modprobing radeon kernel
module (with runpm=1). I'm not able to provide any other debug output as
display is off and kernel crashing... Problem is reproducable always on
notebook Dell Latitude E6440 which have muxless AMD Radeon HD 8690M graphic
card.

Black screen is probably caused by intel driver at line:
[ 171.913779] i915: switched off

And kernel crash by NULL derefence:
[ 173.442690] BUG: unable to handle kernel NULL pointer dereference at
0000000000000008

My AMD graphics card is identified by lspci -nn as:
01:00.0 Display controller [0380]: Advanced Micro Devices, Inc. [AMD/ATI] Sun
XT [Radeon HD 8670A/8670M/8690M] [1002:6660]