From cd2523569a733d85788b6fc016e4e23cb3549a25 Mon Sep 17 00:00:00 2001 From: Gabriel Krisman Bertazi Date: Thu, 16 Feb 2017 14:44:42 -0200 Subject: [PATCH] drm: Always prepare null framebuffer in transitional helper Despite the documentation claim that cleanup_fb will match prior calls to prepare_fb, in case of NULL framebuffers in the transitional helpers, the code will skip the call to prepare_fb but not the corresponding cleanup_fb call. This asymmetry in semantics is unnecessarily surprising for developers transitioning drivers to atomic model, specially because the final atomic handlers don't have the issue - the prepare_fb is always called, despite the new state framebuffer being null. The only current user of the transitional helper that doesn't take care of null framebuffers explicitly inside the prepare_fb hook is atmel_hlcdc, so we take special care to make sure we don't break anything there. Signed-off-by: Gabriel Krisman Bertazi Signed-off-by: Daniel Vetter Link: http://patchwork.freedesktop.org/patch/msgid/20170216164442.28704-1-krisman@collabora.co.uk --- drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_plane.c | 3 +++ drivers/gpu/drm/drm_plane_helper.c | 3 +-- 2 files changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_plane.c b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_plane.c index bd2791c4b002..886ed5d8e304 100644 --- a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_plane.c +++ b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_plane.c @@ -772,6 +772,9 @@ static int atmel_hlcdc_plane_prepare_fb(struct drm_plane *p, drm_plane_state_to_atmel_hlcdc_plane_state(s); int ret; + if (!new_state->fb) + return 0; + ret = atmel_hlcdc_layer_update_start(&plane->layer); if (!ret) state->prepared = true; diff --git a/drivers/gpu/drm/drm_plane_helper.c b/drivers/gpu/drm/drm_plane_helper.c index 148688fb920a..d8639e46bd2b 100644 --- a/drivers/gpu/drm/drm_plane_helper.c +++ b/drivers/gpu/drm/drm_plane_helper.c @@ -450,8 +450,7 @@ int drm_plane_helper_commit(struct drm_plane *plane, goto out; } - if (plane_funcs->prepare_fb && plane_state->fb && - plane_state->fb != old_fb) { + if (plane_funcs->prepare_fb && plane_state->fb != old_fb) { ret = plane_funcs->prepare_fb(plane, plane_state); if (ret)