From 0936f0e54426177b0f0263ddf806ed5e13487db6 Mon Sep 17 00:00:00 2001 From: Dmitry Baryshkov Date: Sun, 22 Dec 2024 07:00:41 +0200 Subject: [PATCH 1617/5403] drm/atomic-helper: document drm_atomic_helper_check() restrictions The drm_atomic_helper_check() calls drm_atomic_helper_check_modeset() insternally. Document that corresponding restrictions also apply to the drivers that call the former function (as it's easy to miss the documentation for the latter function). Reviewed-by: Simona Vetter Reviewed-by: Abhinav Kumar Link: https://patchwork.freedesktop.org/patch/msgid/20241222-drm-dirty-modeset-v1-1-0e76a53eceb9@linaro.org Signed-off-by: Dmitry Baryshkov --- drivers/gpu/drm/drm_atomic_helper.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c index 40e4e1b6c911..3034ba09c0ee 100644 --- a/drivers/gpu/drm/drm_atomic_helper.c +++ b/drivers/gpu/drm/drm_atomic_helper.c @@ -1087,6 +1087,15 @@ EXPORT_SYMBOL(drm_atomic_helper_check_planes); * For example enable/disable of a cursor plane which have fixed zpos value * would trigger all other enabled planes to be forced to the state change. * + * IMPORTANT: + * + * As this function calls drm_atomic_helper_check_modeset() internally, its + * restrictions also apply: + * Drivers which set &drm_crtc_state.mode_changed (e.g. in their + * &drm_plane_helper_funcs.atomic_check hooks if a plane update can't be done + * without a full modeset) _must_ call drm_atomic_helper_check_modeset() + * function again after that change. + * * RETURNS: * Zero for success or -errno */ -- 2.54.0