[PATCH 1/2] drm/radeon: Only enable and handle pageflip interrupts when needed

[Michel Dänzer]

On 26.06.2014 19:39, Christian König wrote:
> Am 26.06.2014 11:29, schrieb Michel Dänzer:
>> From: Michel Dänzer <michel.daenzer at amd.com>
>>
>> Prevents radeon_crtc_handle_flip() from running before
>> radeon_flip_work_func(), resulting in a kernel panic due to the BUG_ON()
>> in drm_vblank_put().
>>
>> Tested-by: Dieter Nützel <Dieter at nuetzel-hh.de>
>> Signed-off-by: Michel Dänzer <michel.daenzer at amd.com>
> 
> Does patch #2 alone fixes the problem as well?

It should avoid the panic as well.


> I would rather want to avoid turning the pflip interrupt on and off.

What's the problem with that? It's not like we're saving any register
writes by not doing it.

The diagnostic messages Dieter was getting with only patch #2 show that
the pflip interrupt often triggers unnecessarily, potentially wasting
power by waking up the CPU from a power saving state pointlessly.


-- 
Earthling Michel Dänzer            |                  http://www.amd.com
Libre software enthusiast          |                Mesa and X developer