https://bugs.freedesktop.org/show_bug.cgi?id=69365

Priority: medium Bug ID: 69365 Assignee: dri-devel@lists.freedesktop.org Summary: vgaswitcheroo crashes when passing "OFF" to the "switch" file Severity: normal Classification: Unclassified OS: Linux (All) Reporter: lbdkmjdf@sharklasers.com Hardware: Other Status: NEW Version: unspecified Component: DRM/Radeon Product: DRI

I have an HP laptop with dual AMD graphics cards (radeon HD 6520g + HD 6750M) running Ubuntu 13.10 beta1, kernel 3.11.0-7-generic amd64. This command # echo "OFF" > /sys/kernel/debug/vgaswitcheroo/switch throws a WARNING in the kernel logs, after which the folder /sys/kernel/debug/vgaswitcheroo/ and the dGPU disappear (as noted in the logs) (and power usage is notably lowered, guessing from the temperatures).

dmesg: http://pastebin.com/Pb7ELyqP , lines 1196+

Someone else in the #radeon channel also found this report: http://lists.freedesktop.org/archives/dri-devel/2013-September/045157.html which links to another old report from the same person.

Thanks.