Commit 92890583 authored Jan 19, 2015 by Matt Roper Committed by Daniel Vetter Jan 26, 2015

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 ab58e338
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Mon Nov 24 20:42:42 2014 +0100

    drm/atomic-helper: Skip vblank waits for unchanged fbs

Reported-by: Jeremiah Mahler <jmmahler@gmail.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=88540


Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Tested-by: Tested-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

parent 281d1bbd

drivers/gpu/drm/drm_plane_helper.c

+9 −1

Original line number	Original line	Diff line number	Diff line
	@@ -435,7 +435,8 @@ int drm_plane_helper_commit(struct drm_plane *plane,
	goto out;		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);		ret = plane_funcs->prepare_fb(plane, plane_state->fb);
	if (ret)		if (ret)
	goto out;		goto out;
	@@ -456,6 +457,13 @@ int drm_plane_helper_commit(struct drm_plane *plane,
	crtc_funcs[i]->atomic_flush(crtc[i]);		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++) {		for (i = 0; i < 2; i++) {
	if (!crtc[i])		if (!crtc[i])
	continue;		continue;