[PATCH] [RFC] drm/radeon: clear WC flag when moving bo from vram to gtt

[Michel Dänzer]

On 24/04/17 07:01 PM, Julien Isorce wrote:
> 
> On 24 April 2017 at 10:51, Christian König <deathsimple at vodafone.de
> <mailto:deathsimple at vodafone.de>> wrote:
> 
>     Am 24.04.2017 um 11:42 schrieb Julien Isorce:
> 
>         But re-add the flag is the bo is moved back to vram.
> 
>         This fixes "ring 0/3 stalled" issue which happens when the driver
>         evicts bo from vram to gtt, at least on TAHITI and CAPVERDE.
> 
> 
>     Interesting find, but NAK on the approach for fixing it.
> 
> 
> Thx for the comments.
>  
> 
> 
>     If WC mappings don't work for TAHITI and CAPVERDE we need to figure
>     out why or at least disable them for those hardware generations in
>     general.
> 
> 
> Should I extend
> https://cgit.freedesktop.org/~agd5f/linux/tree/drivers/gpu/drm/radeon/radeon_object.c?h=amd-staging-4.9#n228
> to BONAIRE (which will include VERDE and TAHITI) ? (to match
> https://cgit.freedesktop.org/~agd5f/linux/tree/drivers/gpu/drm/radeon/radeon_ib.c?h=amd-staging-4.9#n199 )

Not sure the issue is widespread / systemic enough to justify that
upstream. You can do whatever you deem appropriate in your project, of
course.


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