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@xxxxxxx>
---
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);
