[Why] Atomic check can't truly be non-blocking if amdgpu_dm is waiting for hw_done and flip_done in atomic check. This introduces waits when any previous non-blocking commits queued work on a worker thread and a new atomic commit attempts to do another full update/modeset.
[How] Drop the waits and move the global lock acqusition into atomic check. This is fine to do since commit tail waits for these dependencies before calling amdgpu_dm_atomic_commit_tail. This is only safe as long as DC never queries anything from within current_state when doing validation in atomic_check. This is the case as of writing, but any future uses of dc->current_state from within atomic_check should be considered incorrect. Cc: Harry Wentland <[email protected]> Cc: Leo Li <[email protected]> Signed-off-by: Nicholas Kazlauskas <[email protected]> --- .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 58 ++----------------- 1 file changed, 6 insertions(+), 52 deletions(-) diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c index 3ae438d9849f..fe21bb86b66a 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c @@ -5078,57 +5078,6 @@ void dm_restore_drm_connector_state(struct drm_device *dev, dm_force_atomic_commit(&aconnector->base); } -/* - * Grabs all modesetting locks to serialize against any blocking commits, - * Waits for completion of all non blocking commits. - */ -static int do_aquire_global_lock(struct drm_device *dev, - struct drm_atomic_state *state) -{ - struct drm_crtc *crtc; - struct drm_crtc_commit *commit; - long ret; - - /* - * Adding all modeset locks to aquire_ctx will - * ensure that when the framework release it the - * extra locks we are locking here will get released to - */ - ret = drm_modeset_lock_all_ctx(dev, state->acquire_ctx); - if (ret) - return ret; - - list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) { - spin_lock(&crtc->commit_lock); - commit = list_first_entry_or_null(&crtc->commit_list, - struct drm_crtc_commit, commit_entry); - if (commit) - drm_crtc_commit_get(commit); - spin_unlock(&crtc->commit_lock); - - if (!commit) - continue; - - /* - * Make sure all pending HW programming completed and - * page flips done - */ - ret = wait_for_completion_interruptible_timeout(&commit->hw_done, 10*HZ); - - if (ret > 0) - ret = wait_for_completion_interruptible_timeout( - &commit->flip_done, 10*HZ); - - if (ret == 0) - DRM_ERROR("[CRTC:%d:%s] hw_done or flip_done " - "timed out\n", crtc->base.id, crtc->name); - - drm_crtc_commit_put(commit); - } - - return ret < 0 ? ret : 0; -} - void set_freesync_on_stream(struct amdgpu_display_manager *dm, struct dm_crtc_state *new_crtc_state, struct dm_connector_state *new_con_state, @@ -5793,7 +5742,12 @@ static int amdgpu_dm_atomic_check(struct drm_device *dev, if (ret) goto fail; - ret = do_aquire_global_lock(dev, state); + /* + * This should be replaced with finer locking on the + * on the appropriate resources when possible. + * For now it's safer to grab everything. + */ + ret = drm_modeset_lock_all_ctx(dev, state->acquire_ctx); if (ret) goto fail; -- 2.17.1 _______________________________________________ amd-gfx mailing list [email protected] https://lists.freedesktop.org/mailman/listinfo/amd-gfx
