From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id BB643606A335 for ; Tue, 3 Nov 2026 22:59:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=HhnoMRig Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 7C7C110F8C9; Tue, 3 Nov 2026 22:59:28 +0000 (UTC) Received: from tor.source.kernel.org (tor.source.kernel.org [172.105.4.254]) by gabe.freedesktop.org (Postfix) with ESMTPS id C20F910F8C9; Tue, 3 Nov 2026 22:59:22 +0000 (UTC) Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id 0A6DE60AB0; Tue, 3 Nov 2026 22:59:22 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7B2151F000C1; Tue, 3 Nov 2026 22:59:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793746761; bh=W4TleEYDDiKIphcGn6vgwMRIJGKRuYmsVo8RTX/3EgA=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=HhnoMRigZTSSqoy++oeCntLL6knELqqDYTf+zsBzlwsKBDMlvBoSdELxm3xE1E16a q9B3LyH90Ku/FN66ctfwIYCVtBaK0njxIRBSx/jnDvgcA+p0MCQ25IUh0pU8JwRZyT EkW3sN+ftXwPUF+FsONxNiFF7NYXnbzrPXHXmvrw4iy7R96mj+tdQ4h75qiPyykz8a IY8uTG/lrJGc8+tW6Uo6Xp6TnRw6IORox56wwRdT+ZyLCs2kf2SpyJKNTq4woXRS1y s6evzvnTDl2E8J0mubdT5uugF5r/PaDdND3+bJ8YdNqYulzxFmSj6a4yBG7CXEQkT8 L9N1dzFm6zJTg== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [PATCH v11 10/12] drm/gud: add connector luminance support To: =?utf-8?b?TWFyaW8gTGltb25jaWVsbG8gKEFNRCk=?= Cc: dri-devel@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, intel-xe@lists.freedesktop.org In-Reply-To: <20261103-superm1-backlight-property-v11-10-00cce7b2ba22@kernel.org> References: <20261103-superm1-backlight-property-v11-0-00cce7b2ba22@kernel.org> <20261103-superm1-backlight-property-v11-10-00cce7b2ba22@kernel.org> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Tue, 03 Nov 2026 22:59:21 +0000 X-BeenThere: intel-xe@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel Xe graphics driver List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: sashiko-reviews@lists.linux.dev Sender: "Intel-xe" X-Spam-Status: No, score=-10.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,T_SPF_TEMPERROR autolearn=unavailable autolearn_force=no version=4.0.1 X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 X-Archived-By: 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 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/gu= d_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_co= nnector *connector, > struct drm_connector_state *old_state; > =20 > new_state =3D drm_atomic_get_new_connector_state(state, connector); > + old_state =3D 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 !=3D new_state->luminance) > + new_state->tv.brightness =3D 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 !=3D new_state->tv.margins.left || ... old_state->tv.brightness !=3D new_state->tv.brightness || ...) new_crtc_state->connectors_changed =3D 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? --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20261103-superm1-ba= cklight-property-v11-0-00cce7b2ba22@kernel.org?part=3D10