On Thu, Mar 12, 2015 at 10:55 PM, Michel Dänzer wrote: > On 12.03.2015 22:09, Alex Deucher wrote: >> On Thu, Mar 12, 2015 at 5:23 AM, Christian König >> wrote: >>> On 12.03.2015 10:02, Michel Dänzer wrote: >>>> >>>> On 12.03.2015 06:14, Alex Deucher wrote: >>>>> >>>>> On Wed, Mar 11, 2015 at 4:51 PM, Alex Deucher >>>>> wrote: >>>>>> >>>>>> On Wed, Mar 11, 2015 at 2:21 PM, Christian König >>>>>> wrote: >>>>>>> >>>>>>> On 11.03.2015 16:44, Alex Deucher wrote: >>>>>>>> >>>>>>>> radeon_bo_create() calls radeon_ttm_placement_from_domain() >>>>>>>> before ttm_bo_init() is called. radeon_ttm_placement_from_domain() >>>>>>>> uses the ttm bo size to determine when to select top down >>>>>>>> allocation but since the ttm bo is not initialized yet the >>>>>>>> check is always false. >>>>>>>> >>>>>>>> Noticed-by: Oded Gabbay >>>>>>>> Signed-off-by: Alex Deucher >>>>>>>> Cc: stable@vger.kernel.org >>>>>>> >>>>>>> >>>>>>> And I was already wondering why the heck the BOs always made this >>>>>>> ping/pong >>>>>>> in memory after creation. >>>>>>> >>>>>>> Patch is Reviewed-by: Christian König >>>>>> >>>>>> And fixing that promptly broke VCE due to vram location requirements. >>>>>> Updated patch attached. Thoughts? >>>>> >>>>> And one more take to make things a bit more explicit for static kernel >>>>> driver allocations. >>>> >>>> struct ttm_place::lpfn is honoured even with TTM_PL_FLAG_TOPDOWN, so >>>> latter should work with RADEON_GEM_CPU_ACCESS. It sounds like the >>>> problem is really that some BOs are expected to be within a certain >>>> range from the beginning of VRAM, but lpfn isn't set accordingly. It >>>> would be better to fix that by setting lpfn directly than indirectly via >>>> RADEON_GEM_CPU_ACCESS. >>> >>> >>> Yeah, agree. We should probably try to find the root cause of this instead. >>> >>> As far as I know VCE has no documented limitation on where buffers are >>> placed (unlike UVD). So this is a bit strange. Are you sure that it isn't >>> UVD which breaks here? >> >> It's definitely VCE, I don't know why UVD didn't have a problem. I >> considered using pin_restricted to make sure it got pinned in the CPU >> visible region, but that had two problems: 1. it would end up getting >> migrated when pinned, > > Maybe something like radeon_uvd_force_into_uvd_segment() is needed for > VCE as well? > > >> 2. it would end up at the top of the restricted >> region since the top down flag is set which would end up fragmenting >> vram. > > If that's an issue (which outweighs the supposed benefit of > TTM_PL_FLAG_TOPDOWN), then again the proper solution would be not to set > TTM_PL_FLAG_TOPDOWN when rbo->placements[i].lpfn != 0 and smaller than > the whole available region, instead of checking for VRAM and > RADEON_GEM_CPU_ACCESS. > How about something like the attached patch? I'm not really sure about the restrictions for the UVD and VCE fw and stack/heap buffers, but this seems to work. It seems like the current UVD/VCE code works by accident since the check for TOPDOWN fails. Alex