Bug 116581

Summary:	[radeon] radeon power management with hybrid graphics no longer works after commit e64c952efb8e0c15ae82cec8e455ab4910690ef1
Product:	Drivers	Reporter:	Rafael Ristovski (rafael.ristovski)
Component:	Video(Other)	Assignee:	drivers_video-other
Status:	NEW ---
Severity:	high
Priority:	P1
Hardware:	x86-64
OS:	Linux
Kernel Version:	4.4.7	Subsystem:
Regression:	Yes	Bisected commit-id:
Attachments:	dmesg

Description Rafael Ristovski 2016-04-17 14:36:12 UTC

Created attachment 213181 [details]
dmesg

The following commit breaks power management on my Dell Inspiron 3537 with hybrid Radeon HD 8850M graphics, 

https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=e64c952efb8e0c15ae82cec8e455ab4910690ef1

This causes VCE to fail to init and the GPU to hang for 10s. After this short hang, the GPU works exactly once - if it ever shuts down automatically it will be unable to power on.

Reverting the commit fixes this.

Below is an dmesg extract