drm/msm: fix fb references in async update

BugLink: https://bugs.launchpad.net/bugs/1838700
commit 474d952b4870cfbdc55d3498f4d498775fe77e81 upstream.

Async update callbacks are expected to set the old_fb in the new_state
so prepare/cleanup framebuffers are balanced.

Cc: <stable@vger.kernel.org> # v4.14+
Fixes: 224a4c970987 ("drm/msm: update cursors asynchronously through atomic")
Suggested-by: Boris Brezillon <boris.brezillon@collabora.com>
Signed-off-by: Helen Koike <helen.koike@collabora.com>
Acked-by: Rob Clark <robdclark@gmail.com>
Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190603165610.24614-4-helen.koike@collabora.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>

diff --git a/drivers/gpu/drm/msm/mdp/mdp5/mdp5_plane.c b/drivers/gpu/drm/msm/mdp/mdp5/mdp5_plane.c
index be50445f9901a2463425fe9d803f4f2f74a9d726..345696c8ad0da4eb81b2bdfa52bf524808bacd6d 100644 (file)
--- a/drivers/gpu/drm/msm/mdp/mdp5/mdp5_plane.c
+++ b/drivers/gpu/drm/msm/mdp/mdp5/mdp5_plane.c
@@ -526,6 +526,8 @@ static int mdp5_plane_atomic_async_check(struct drm_plane *plane,
 static void mdp5_plane_atomic_async_update(struct drm_plane *plane,
                                           struct drm_plane_state *new_state)
 {
+       struct drm_framebuffer *old_fb = plane->state->fb;
+
        plane->state->src_x = new_state->src_x;
        plane->state->src_y = new_state->src_y;
        plane->state->crtc_x = new_state->crtc_x;
@@ -548,6 +550,8 @@ static void mdp5_plane_atomic_async_update(struct drm_plane *plane,
 
        *to_mdp5_plane_state(plane->state) =
                *to_mdp5_plane_state(new_state);
+
+       new_state->fb = old_fb;
 }
 
 static const struct drm_plane_helper_funcs mdp5_plane_helper_funcs = {