From: Matt Roper Date: Mon, 19 Jan 2015 16:31:49 +0000 (-0800) Subject: drm/plane-helper: Skip prepare_fb/cleanup_fb when newfb==oldfb X-Git-Tag: firefly_0821_release~176^2~2312^2~24^2~8 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=92890583627ee2a0518e55b063fcff86826fef96;p=firefly-linux-kernel-4.4.55.git drm/plane-helper: Skip prepare_fb/cleanup_fb when newfb==oldfb When commiting a plane update where the framebuffer doesn't change, we can skip the prepare_fb/cleanup_fb steps. This also allows us to avoid an unnecessary vblank wait at the end of the operation when we're just moving a plane and not changing its image (e.g., for a cursor). At the moment, i915 is the only upstream driver using the transitional plane helpers, and thus the only driver affected by this change. Note that this replicates a corresponding change in the atomic helpers implemented in commit ab58e3384b9f9863bfd029b458ff337d381bf6d2 Author: Daniel Vetter Date: Mon Nov 24 20:42:42 2014 +0100 drm/atomic-helper: Skip vblank waits for unchanged fbs Reported-by: Jeremiah Mahler Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=88540 Signed-off-by: Matt Roper Tested-by: Tested-by: Rodrigo Vivi Signed-off-by: Daniel Vetter --- diff --git a/drivers/gpu/drm/drm_plane_helper.c b/drivers/gpu/drm/drm_plane_helper.c index f24c4cfe674b..7a5814afe31a 100644 --- a/drivers/gpu/drm/drm_plane_helper.c +++ b/drivers/gpu/drm/drm_plane_helper.c @@ -435,7 +435,8 @@ int drm_plane_helper_commit(struct drm_plane *plane, goto out; } - if (plane_funcs->prepare_fb && plane_state->fb) { + if (plane_funcs->prepare_fb && plane_state->fb && + plane_state->fb != old_fb) { ret = plane_funcs->prepare_fb(plane, plane_state->fb); if (ret) goto out; @@ -456,6 +457,13 @@ int drm_plane_helper_commit(struct drm_plane *plane, crtc_funcs[i]->atomic_flush(crtc[i]); } + /* + * If we only moved the plane and didn't change fb's, there's no need to + * wait for vblank. + */ + if (plane->state->fb == old_fb) + goto out; + for (i = 0; i < 2; i++) { if (!crtc[i]) continue;