Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider: - [High] drm/gud: LUMINANCE updates in gud_connector_atomic_check() require modeset --
commit 8034990b85e36e57451a40c677e5ac4037438eda Author: Mario Limonciello <[email protected]> drm/gud: add connector luminance support This commit exposes GUD display brightness through the connector LUMINANCE property when CONFIG_DRM_LUMINANCE is enabled, mirroring luminance changes into tv.brightness during atomic check. > diff --git a/drivers/gpu/drm/gud/gud_connector.c > b/drivers/gpu/drm/gud/gud_connector.c > index ddbf3b3ebbca8..bfb298bbc9b51 100644 > --- a/drivers/gpu/drm/gud/gud_connector.c > +++ b/drivers/gpu/drm/gud/gud_connector.c > @@ -292,10 +292,19 @@ static int gud_connector_atomic_check(struct > drm_connector *connector, > struct drm_connector_state *old_state; > > new_state = drm_atomic_get_new_connector_state(state, connector); > + old_state = drm_atomic_get_old_connector_state(state, connector); > + > + /* > + * LUMINANCE is sent to the device as tv.brightness in the same commit, > + * the brightness change below then triggers GUD_REQ_SET_STATE_CHECK. > + */ > + if (connector->luminance_property && > + old_state->luminance != new_state->luminance) > + new_state->tv.brightness = new_state->luminance; [Severity: High] Will mirroring new_state->luminance into new_state->tv.brightness here cause non-modeset atomic commits that update LUMINANCE to fail with -EINVAL? In gud_connector_atomic_check(), changing new_state->tv.brightness sets new_crtc_state->connectors_changed: if (old_state->tv.margins.left != new_state->tv.margins.left || ... old_state->tv.brightness != new_state->tv.brightness || ...) new_crtc_state->connectors_changed = true; When a userspace compositor updates LUMINANCE in a normal atomic commit without DRM_MODE_ATOMIC_ALLOW_MODESET: drm_mode_atomic_ioctl() -> drm_atomic_check_only() -> drm_atomic_helper_check() -> drm_atomic_helper_check_modeset() -> gud_connector_atomic_check() -> drm_atomic_helper_check_planes() -> gud_plane_atomic_check() gud_plane_atomic_check() sees crtc_state->connectors_changed and sends GUD_REQ_SET_STATE_CHECK to the USB device, but drm_atomic_check_only() then rejects the commit because drm_atomic_crtc_needs_modeset(new_crtc_state) is true when connectors_changed is set: if (!state->allow_modeset) { for_each_new_crtc_in_state(state, crtc, new_crtc_state, i) { if (drm_atomic_crtc_needs_modeset(new_crtc_state)) { drm_dbg_atomic(dev, "[CRTC:%d:%s] requires full modeset\n", crtc->base.id, crtc->name); return -EINVAL; } } } Even if DRM_MODE_ATOMIC_ALLOW_MODESET is passed, wouldn't setting connectors_changed force a full CRTC modeset on every brightness adjustment? -- Sashiko AI review ยท https://sashiko.dev/#/patchset/20261103-superm1-backlight-property-v11-0-00cce7b2b...@kernel.org?part=10
