From: Helen Koike helen.koike@collabora.com
commit d985a3533274ef7dd1ccb25cb05a72259b25268f upstream.
In the case of async update, modifications are done in place, i.e. in the current plane state, so the new_state is prepared and the new_state is cleaned up (instead of the old_state, unlike what happens in a normal sync update). To cleanup the old_fb properly, it needs to be placed in the new_state in the end of async_update, so cleanup call will unreference the old_fb correctly.
Also, the previous code had a:
plane_state = plane->funcs->atomic_duplicate_state(plane); ... swap(plane_state, plane->state);
if (plane->state->fb && plane->state->fb != new_state->fb) { ... }
Which was wrong, as the fb were just assigned to be equal, so this if statement nevers evaluates to true.
Another details is that the function drm_crtc_vblank_get() can only be called when vop->is_enabled is true, otherwise it has no effect and trows a WARN_ON().
Calling drm_atomic_set_fb_for_plane() (which get a referent of the new fb and pus the old fb) is not required, as it is taken care by drm_mode_cursor_universal() when calling drm_atomic_helper_update_plane().
Fixes: 15609559a834 ("drm/rockchip: update cursors asynchronously through atomic.") Cc: stable@vger.kernel.org # v4.20+ Signed-off-by: Helen Koike helen.koike@collabora.com Signed-off-by: Boris Brezillon boris.brezillon@collabora.com Link: https://patchwork.freedesktop.org/patch/msgid/20190603165610.24614-2-helen.k... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/gpu/drm/rockchip/rockchip_drm_vop.c | 49 ++++++++++++++-------------- 1 file changed, 25 insertions(+), 24 deletions(-)
--- a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c +++ b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c @@ -924,29 +924,17 @@ static void vop_plane_atomic_async_updat struct drm_plane_state *new_state) { struct vop *vop = to_vop(plane->state->crtc); - struct drm_plane_state *plane_state; + struct drm_framebuffer *old_fb = plane->state->fb;
- plane_state = plane->funcs->atomic_duplicate_state(plane); - plane_state->crtc_x = new_state->crtc_x; - plane_state->crtc_y = new_state->crtc_y; - plane_state->crtc_h = new_state->crtc_h; - plane_state->crtc_w = new_state->crtc_w; - plane_state->src_x = new_state->src_x; - plane_state->src_y = new_state->src_y; - plane_state->src_h = new_state->src_h; - plane_state->src_w = new_state->src_w; - - if (plane_state->fb != new_state->fb) - drm_atomic_set_fb_for_plane(plane_state, new_state->fb); - - swap(plane_state, plane->state); - - if (plane->state->fb && plane->state->fb != new_state->fb) { - drm_framebuffer_get(plane->state->fb); - WARN_ON(drm_crtc_vblank_get(plane->state->crtc) != 0); - drm_flip_work_queue(&vop->fb_unref_work, plane->state->fb); - set_bit(VOP_PENDING_FB_UNREF, &vop->pending); - } + plane->state->crtc_x = new_state->crtc_x; + plane->state->crtc_y = new_state->crtc_y; + plane->state->crtc_h = new_state->crtc_h; + plane->state->crtc_w = new_state->crtc_w; + plane->state->src_x = new_state->src_x; + plane->state->src_y = new_state->src_y; + plane->state->src_h = new_state->src_h; + plane->state->src_w = new_state->src_w; + swap(plane->state->fb, new_state->fb);
if (vop->is_enabled) { rockchip_drm_psr_inhibit_get_state(new_state->state); @@ -955,9 +943,22 @@ static void vop_plane_atomic_async_updat vop_cfg_done(vop); spin_unlock(&vop->reg_lock); rockchip_drm_psr_inhibit_put_state(new_state->state); - }
- plane->funcs->atomic_destroy_state(plane, plane_state); + /* + * A scanout can still be occurring, so we can't drop the + * reference to the old framebuffer. To solve this we get a + * reference to old_fb and set a worker to release it later. + * FIXME: if we perform 500 async_update calls before the + * vblank, then we can have 500 different framebuffers waiting + * to be released. + */ + if (old_fb && plane->state->fb != old_fb) { + drm_framebuffer_get(old_fb); + WARN_ON(drm_crtc_vblank_get(plane->state->crtc) != 0); + drm_flip_work_queue(&vop->fb_unref_work, old_fb); + set_bit(VOP_PENDING_FB_UNREF, &vop->pending); + } + } }
static const struct drm_plane_helper_funcs plane_helper_funcs = {