Re: [PATCH 13/18] drm/amdgpu/dc: Stop dma_resv_lock inversion in commit_tail

Hi Daniel,

On 04/06/2020 10:12, Daniel Vetter wrote: [...]

@@ -6910,7 +6910,11 @@ static void amdgpu_dm_commit_planes(struct drm_atomic_state *state, * explicitly on fences instead * and in general should be called for * blocking commit to as per framework helpers

•  *
  

•  * Yes, this deadlocks, since you're calling dma_resv_lock in a
  

•  * path that leads to a dma_fence_signal(). Don't do that.
  

  */

+#if 0 r = amdgpu_bo_reserve(abo, true); if (unlikely(r != 0)) DRM_ERROR("failed to reserve buffer before flip\n"); @@ -6920,6 +6924,12 @@ static void amdgpu_dm_commit_planes(struct drm_atomic_state *state, tmz_surface = amdgpu_bo_encrypted(abo);

amdgpu_bo_unreserve(abo);

+#endif

• /*
  

•  * this races anyway, so READ_ONCE isn't any better or worse
  

•  * than the stuff above. Except the stuff above can deadlock.
  

•  */
  

• tiling_flags = READ_ONCE(abo->tiling_flags);
  

With this change "tmz_surface" won't be initialized properly. Adding the following line should fix it:

tmz_surface = READ_ONCE(abo->flags) & AMDGPU_GEM_CREATE_ENCRYPTED;

Pierre-Eric

fill_dc_plane_info_and_addr(
	dm->adev, new_plane_state, tiling_flags,