From: Thomas Zimmermann <tzimmermann@xxxxxxx> commit d6ddbd5c97d1b9156646ac5c42b8851edd664ee2 upstream. Suspending failed because there's no mode if the CRTC is being disabled. Early-out in this case. This fixes runtime PM for ast. v3: * fixed commit message v2: * added Tested-by/Reported-by tags * added Fixes tags and CC (Sam) * improved comment Signed-off-by: Thomas Zimmermann <tzimmermann@xxxxxxx> Reported-by: Cary Garrett <cogarre@xxxxxxxxx> Tested-by: Cary Garrett <cogarre@xxxxxxxxx> Reviewed-by: Daniel Vetter <daniel.vetter@xxxxxxxx> Fixes: b48e1b6ffd28 ("drm/ast: Add CRTC helpers for atomic modesetting") Cc: Thomas Zimmermann <tzimmermann@xxxxxxx> Cc: Gerd Hoffmann <kraxel@xxxxxxxxxx> Cc: Dave Airlie <airlied@xxxxxxxxxx> Cc: Daniel Vetter <daniel.vetter@xxxxxxxx> Cc: Sam Ravnborg <sam@xxxxxxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> # v5.6+ Link: https://patchwork.freedesktop.org/patch/msgid/20200507090640.21561-1-tzimmermann@xxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/gpu/drm/ast/ast_mode.c | 3 +++ 1 file changed, 3 insertions(+) --- a/drivers/gpu/drm/ast/ast_mode.c +++ b/drivers/gpu/drm/ast/ast_mode.c @@ -802,6 +802,9 @@ static int ast_crtc_helper_atomic_check( return -EINVAL; } + if (!state->enable) + return 0; /* no mode checks if CRTC is being disabled */ + ast_state = to_ast_crtc_state(state); format = ast_state->format;