drm/amdgpu: check ring being ready before using
authorDing Pixel <pding@amd.com>
Wed, 18 Jan 2017 09:26:38 +0000 (17:26 +0800)
committerAlex Deucher <alexander.deucher@amd.com>
Mon, 23 Jan 2017 21:47:01 +0000 (16:47 -0500)
commitc5f21c9f878b8dcd54d0b9739c025ca73cb4c091
tree1eb4020ee24a97f3c59e02d387856feca0278a8c
parent932790109f62aa52bdb4bb62aa66653c0b51bc75
drm/amdgpu: check ring being ready before using

Return success when the ring is properly initialized, otherwise return
failure.

Tonga SRIOV VF doesn't have UVD and VCE engines, the initialization of
these IPs is bypassed. The system crashes if application submit IB to
their rings which are not ready to use. It could be a common issue if
IP having ring buffer is disabled for some reason on specific ASIC, so
it should check the ring being ready to use.

Bug: amdgpu_test crashes system on Tonga VF.

Signed-off-by: Ding Pixel <Pixel.Ding@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c