On 05/10/2021 11:27, Christian König wrote:
Am 05.10.21 um 09:53 schrieb Tvrtko Ursulin:
On 01/10/2021 11:06, Christian König wrote:
Makes the handling a bit more complex, but avoids the use of dma_resv_get_excl_unlocked().
Signed-off-by: Christian König christian.koenig@amd.com
drivers/gpu/drm/drm_gem_atomic_helper.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/drm_gem_atomic_helper.c b/drivers/gpu/drm/drm_gem_atomic_helper.c index e570398abd78..21ed930042b8 100644 --- a/drivers/gpu/drm/drm_gem_atomic_helper.c +++ b/drivers/gpu/drm/drm_gem_atomic_helper.c @@ -143,6 +143,7 @@ */ int drm_gem_plane_helper_prepare_fb(struct drm_plane *plane, struct drm_plane_state *state) { + struct dma_resv_iter cursor; struct drm_gem_object *obj; struct dma_fence *fence; @@ -150,9 +151,17 @@ int drm_gem_plane_helper_prepare_fb(struct drm_plane *plane, struct drm_plane_st return 0; obj = drm_gem_fb_get_obj(state->fb, 0); - fence = dma_resv_get_excl_unlocked(obj->resv); - drm_atomic_set_fence_for_plane(state, fence); + dma_resv_iter_begin(&cursor, obj->resv, false); + dma_resv_for_each_fence_unlocked(&cursor, fence) { + dma_fence_get(fence); + dma_resv_iter_end(&cursor); + /* TODO: We only use the first write fence here */
What is the TODO? NB instead?
The drm atomic API can unfortunately handle only one fence and we can certainly have more than that.
- drm_atomic_set_fence_for_plane(state, fence);
+ return 0; + } + dma_resv_iter_end(&cursor); + drm_atomic_set_fence_for_plane(state, NULL);
dma_resv_iter_begin(&cursor, obj->resv, false); dma_resv_for_each_fence_unlocked(&cursor, fence) { dma_fence_get(fence); break; } dma_resv_iter_end(&cursor);
drm_atomic_set_fence_for_plane(state, fence);
Does this work?
Yeah that should work as well.
But overall I am not sure this is nicer. Is the goal to remove dma_resv_get_excl_unlocked as API it just does not happen in this series?
Yes, the only user left is the i915_gem_object_last_write_engine() function and that one you already removed in i915.
To me the above feels clumsier than dma_resv_get_excl_unlocked and you can even view it as open coding that helper. So don't know, someone else can have a casting vote.
I guess if support for more than one fence is coming soon(-ish) do drm atomic api then I could be convinced the iterator here makes sense today.
Regards,
Tvrtko
Regards, Christian.
Regards,
Tvrtko
return 0; } EXPORT_SYMBOL_GPL(drm_gem_plane_helper_prepare_fb);