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(unknown [58.22.7.114]) by smtp.qiye.163.com (Hmail) with ESMTP id 2d931e4b3; Wed, 17 Dec 2025 17:33:38 +0800 (GMT+08:00) From: Damon Ding To: andrzej.hajda@intel.com, neil.armstrong@linaro.org, rfoss@kernel.org Cc: Laurent.pinchart@ideasonboard.com, jonas@kwiboo.se, jernej.skrabec@gmail.com, maarten.lankhorst@linux.intel.com, mripard@kernel.org, tzimmermann@suse.de, airlied@gmail.com, simona@ffwll.ch, shawnguo@kernel.org, s.hauer@pengutronix.de, kernel@pengutronix.de, festevam@gmail.com, inki.dae@samsung.com, sw0312.kim@samsung.com, kyungmin.park@samsung.com, krzk@kernel.org, alim.akhtar@samsung.com, jingoohan1@gmail.com, p.zabel@pengutronix.de, hjc@rock-chips.com, heiko@sntech.de, andy.yan@rock-chips.com, dmitry.baryshkov@oss.qualcomm.com, dianders@chromium.org, m.szyprowski@samsung.com, luca.ceresoli@bootlin.com, jani.nikula@intel.com, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, imx@lists.linux.dev, linux-arm-kernel@lists.infradead.org, linux-samsung-soc@vger.kernel.org, linux-rockchip@lists.infradead.org, Damon Ding Subject: [PATCH v8 01/18] drm/display: bridge_connector: Ensure last bridge determines EDID/modes detection capabilities Date: Wed, 17 Dec 2025 17:33:04 +0800 Message-Id: <20251217093321.3108939-2-damon.ding@rock-chips.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20251217093321.3108939-1-damon.ding@rock-chips.com> References: <20251217093321.3108939-1-damon.ding@rock-chips.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-HM-Tid: 0a9b2ba871dc03a3kunma9c945a29ed9a X-HM-MType: 1 X-HM-Spam-Status: e1kfGhgUHx5ZQUpXWQgPGg8OCBgUHx5ZQUlOS1dZFg8aDwILHllBWSg2Ly tZV1koWUFDSUNOT01LS0k3V1ktWUFJV1kPCRoVCBIfWUFZGhkdGlZKSRgaHkxKS01OGBhWFRQJFh oXVRMBExYaEhckFA4PWVdZGBILWUFZTkNVSUlVTFVKSk9ZV1kWGg8SFR0UWUFZT0tIVUpLSEpKQk 1VSktLVUpCWQY+ DKIM-Signature: a=rsa-sha256; b=QWUz382MLHrh4SaeV+BD/QjhkFn3QXZ1RSqJk7ie6m+cI64udPP/tdQTPQmKK5nD7h15vz83LRECQmGentL2MFzlxdND0wy4tlqlSJnYv8uacHmLKq6YdQ51agMcBMs0Bz8K8OXA5iX4dkKBUmv+wLYiSstROwFiCQthiamIaq8=; s=default; c=relaxed/relaxed; d=rock-chips.com; v=1; bh=ARC0eRZH6xtSv1qtUSRKKwKr4pOZEQIYOR1R2EYV0Ss=; h=date:mime-version:subject:message-id:from; Content-Type: text/plain; charset="utf-8" When multiple bridges are present, EDID detection capability (DRM_BRIDGE_OP_EDID) takes precedence over modes detection (DRM_BRIDGE_OP_MODES). To ensure the above two capabilities are determined by the last bridge in the chain, we handle three cases: Case 1: The later bridge declares only DRM_BRIDGE_OP_MODES - If the previous bridge declares DRM_BRIDGE_OP_EDID, set &drm_bridge_connector.bridge_edid to NULL and set &drm_bridge_connector.bridge_modes to the later bridge. - Ensure modes detection capability of the later bridge will not be ignored. Case 2: The later bridge declares only DRM_BRIDGE_OP_EDID - If the previous bridge declares DRM_BRIDGE_OP_MODES, set &drm_bridge_connector.bridge_modes to NULL and set &drm_bridge_connector.bridge_edid to the later bridge. - Although EDID detection capability has higher priority, this operation is for balance and makes sense. Case 3: the later bridge declares both of them - Assign later bridge as &drm_bridge_connector.bridge_edid and and &drm_bridge_connector.bridge_modes to this bridge. - Just leave transfer of these two capabilities as before. Signed-off-by: Damon Ding Suggested-by: Dmitry Baryshkov Tested-by: Marek Szyprowski --- Changes in v7: - As Luca suggested, simplify the code and related comment. Changes in v8: - Adapt the modifications to the newest bridge_connector driver. --- drivers/gpu/drm/display/drm_bridge_connector.c | 18 ++++++++++++------ 1 file changed, 12 insertions(+), 6 deletions(-) diff --git a/drivers/gpu/drm/display/drm_bridge_connector.c b/drivers/gpu/d= rm/display/drm_bridge_connector.c index a2d30cf9e06d..92b9e8ec520d 100644 --- a/drivers/gpu/drm/display/drm_bridge_connector.c +++ b/drivers/gpu/drm/display/drm_bridge_connector.c @@ -690,9 +690,19 @@ struct drm_connector *drm_bridge_connector_init(struct= drm_device *drm, if (!bridge->ycbcr_420_allowed) connector->ycbcr_420_allowed =3D false; =20 - if (bridge->ops & DRM_BRIDGE_OP_EDID) { + /* + * Ensure the last bridge declares OP_EDID or OP_MODES or both. + */ + if (bridge->ops & DRM_BRIDGE_OP_EDID || bridge->ops & DRM_BRIDGE_OP_MODE= S) { drm_bridge_put(bridge_connector->bridge_edid); - bridge_connector->bridge_edid =3D drm_bridge_get(bridge); + bridge_connector->bridge_edid =3D NULL; + drm_bridge_put(bridge_connector->bridge_modes); + bridge_connector->bridge_modes =3D NULL; + + if (bridge->ops & DRM_BRIDGE_OP_EDID) + bridge_connector->bridge_edid =3D drm_bridge_get(bridge); + if (bridge->ops & DRM_BRIDGE_OP_MODES) + bridge_connector->bridge_modes =3D drm_bridge_get(bridge); } if (bridge->ops & DRM_BRIDGE_OP_HPD) { drm_bridge_put(bridge_connector->bridge_hpd); @@ -702,10 +712,6 @@ struct drm_connector *drm_bridge_connector_init(struct= drm_device *drm, drm_bridge_put(bridge_connector->bridge_detect); bridge_connector->bridge_detect =3D drm_bridge_get(bridge); } - if (bridge->ops & DRM_BRIDGE_OP_MODES) { - drm_bridge_put(bridge_connector->bridge_modes); - bridge_connector->bridge_modes =3D drm_bridge_get(bridge); - } if (bridge->ops & DRM_BRIDGE_OP_HDMI) { if (bridge_connector->bridge_hdmi) return ERR_PTR(-EBUSY); --=20 2.34.1