Bug 69365

Summary:	vgaswitcheroo crashes when passing "OFF" to the "switch" file
Product:	DRI	Reporter:	Jose P. <lbdkmjdf>
Component:	DRM/Radeon	Assignee:	Default DRI bug account <dri-devel>
Status:	RESOLVED FIXED	QA Contact:
Severity:	normal
Priority:	medium
Version:	unspecified
Hardware:	Other
OS:	Linux (All)
Whiteboard:
i915 platform:		i915 features:

Description Jose P. 2013-09-15 01:07:31 UTC

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.

Comment 1 Jose P. 2013-09-17 03:44:34 UTC

Seems to have been fixed in kernel 3.12-rc1 (from http://kernel.ubuntu.com/~kernel-ppa/mainline/v3.12-rc1-saucy/ ).
I don't know how to test it in a better way (other than simply running the above command)... and I don't have other hardware to test it, so please close it if you think it should be closed.

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