From: Ville Syrjälä ville.syrjala@linux.intel.com
The early return in drm_atomic_set_mode_for_crtc() isn't quite right. It would mistakenly return and fail to update crtc_state->enable if someone actually tried to set a zeroed mode on a currently disabled crtc. That should never actually happen in response to any userspace request as the zeroed mode would get rejected earlier. However there is some chance of this happening internally (eg. during hw state readout) so it seems best to not let the state become totally inconsistent.
Additionally the early return will not be taken if we're trying to disable an already disabled crtc. While that is not actually harmful it is inconsistent, so let's handle that case as well.
Testcase: igt/kms_selftest/check_atomic_set_mode_for_crtc Testcase: igt/kms_selftest/check_atomic_set_zeroed_mode_fort_crtc Reviewed-by: Daniel Vetter daniel@ffwll.ch Signed-off-by: Ville Syrjälä ville.syrjala@linux.intel.com --- drivers/gpu/drm/drm_atomic_uapi.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/drm_atomic_uapi.c b/drivers/gpu/drm/drm_atomic_uapi.c index 0d466d3b0809..a3a6a8137af4 100644 --- a/drivers/gpu/drm/drm_atomic_uapi.c +++ b/drivers/gpu/drm/drm_atomic_uapi.c @@ -68,8 +68,13 @@ int drm_atomic_set_mode_for_crtc(struct drm_crtc_state *state, struct drm_mode_modeinfo umode;
/* Early return for no change. */ - if (mode && memcmp(&state->mode, mode, sizeof(*mode)) == 0) - return 0; + if (state->enable) { + if (mode && memcmp(&state->mode, mode, sizeof(*mode)) == 0) + return 0; + } else { + if (!mode) + return 0; + }
drm_property_blob_put(state->mode_blob); state->mode_blob = NULL;