[PATCH 2/3] drm/radeon: Reinstate radeon_gart_restore for GART table in VRAM

[Michel Dänzer]

On 21.01.2015 18:22, Christian König wrote:
> Am 21.01.2015 um 09:36 schrieb Michel Dänzer:
>> From: Michel Dänzer <michel.daenzer at amd.com>
>>
>> The GART table BO has to be moved out of VRAM for suspend/resume. Any
>> updates to the GART table during that time were silently dropped without
>> this change. This caused GPU lockups on resume in some cases, see the bug
>> reports referenced below.
>>
>> This might also make GPU reset more robust in some cases, as we no longer
>> rely on the GART table in VRAM being preserved across the GPU
>> lockup/reset.
>>
>> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=85204
>> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=86267
>> Cc: stable at vger.kernel.org
>> Signed-off-by: Michel Dänzer <michel.daenzer at amd.com>
> 
> Can we make that directly part of radeon_gart_table_vram_pin? Doesn't
> seem to make sense to always need to call both functions.

Good point, fixed in v2.


> Additional to that couldn't we just stop mapping/unmapping the BO in
> radeon_gart_table_vram_pin? As far as I know CPU mapped BOs can still
> move around.

You're probably thinking of userspace mappings. I think the kernel
mapping would continue pointing to the same area of VRAM even while the
BO is evicted from VRAM or pinned back to another area of VRAM.


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