https://bugzilla.kernel.org/show_bug.cgi?id=33812

Summary: radeon with modeset option causes oops as secondary adapter (vgaswitcheroo) Product: Drivers Version: 2.5 Kernel Version: 2.6.38.3 Platform: All OS/Version: Linux Tree: Mainline Status: NEW Severity: high Priority: P1 Component: Video(DRI - non Intel) AssignedTo: drivers_video-dri@kernel-bugs.osdl.org ReportedBy: jcnengel@googlemail.com Regression: Yes

Created an attachment (id=54942) --> (https://bugzilla.kernel.org/attachment.cgi?id=54942) kernel log

System: Lenovo ThinkPad T500 00:02.0 VGA compatible controller: Intel Corporation Mobile 4 Series Chipset Integrated Graphics Controller (rev 07) 01:00.0 VGA compatible controller: ATI Technologies Inc Mobility Radeon HD 3650 using vgaswitcheroo

Trying to load radeon (as a module or in kernel) with modeset not explicitly disabled causes a kernel NULL pointer dereference if i915 has initialised the fb console already. That behaviour did not occur in 2.6.38, only after upgrading to 2.6.38.3 (haven't had the time to bisect yet).

If I disable switching in the BIOS and move to the radeon card as exclusive adapter, everything works fine. with dual graphics stack