From: Takashi Iwai tiwai@suse.de
commit 6d6e732835db92e66c28dbcf258a7e3d3c71420d upstream.
Restore the display mode whne resuming from suspend. Currently, the display remains dark.
On resume, the CRTC's mode does not change, but the 'active' flag changes to 'true'. Taking this into account when considering a mode switch restores the display mode.
The bug is reproducable by using Gnome with udl and observing the adapter's suspend/resume behavior.
Actually, the whole check added in udl_simple_display_pipe_enable() about the crtc_state->mode_changed was bogus. We should drop the whole check and always apply the mode change in this function.
[ tiwai -- Drop the mode_changed check entirely instead, per Daniel's suggestion ]
Fixes: 997d33c35618 ("drm/udl: Inline DPMS code into CRTC enable and disable functions") Cc: stable@vger.kernel.org Suggested-by: Daniel Vetter daniel.vetter@ffwll.ch Reviewed-by: Daniel Vetter daniel.vetter@ffwll.ch Signed-off-by: Takashi Iwai tiwai@suse.de Signed-off-by: Thomas Zimmermann tzimmermann@suse.de Link: https://patchwork.freedesktop.org/patch/msgid/20220908095115.23396-2-tiwai@s... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/gpu/drm/udl/udl_modeset.c | 3 --- 1 file changed, 3 deletions(-)
--- a/drivers/gpu/drm/udl/udl_modeset.c +++ b/drivers/gpu/drm/udl/udl_modeset.c @@ -400,9 +400,6 @@ udl_simple_display_pipe_enable(struct dr
udl_handle_damage(fb, 0, 0, fb->width, fb->height);
- if (!crtc_state->mode_changed) - return; - /* enable display */ udl_crtc_write_mode_to_hw(crtc); }