From 1148ef0c600f641f4ea95b3d8275cc911fd2f232 Mon Sep 17 00:00:00 2001 From: Luca Ceresoli Date: Tue, 7 Apr 2026 14:24:23 +0200 Subject: [PATCH] drm/bridge: imx8mp-hdmi-tx-connector-fixup: show a warning when adding the overlay Describing the HDMI connector in device tree is recommended. While the overlay insertion is a workaround to avoid breaking existing devices, every dts should be improved by adding a connector description. Add a warning to make users aware as far as possible. As a warning line cannot hold all the relevant info, add a detailed comment in the code so it easy to find when the warning is seen. Reviewed-by: Liu Ying Link: https://patch.msgid.link/20260407-drm-lcdif-dbanc-v4-9-247a16e61ef9@bootlin.com Signed-off-by: Luca Ceresoli --- .../bridge/imx/imx8mp-hdmi-tx-connector-fixup.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/drivers/gpu/drm/bridge/imx/imx8mp-hdmi-tx-connector-fixup.c b/drivers/gpu/drm/bridge/imx/imx8mp-hdmi-tx-connector-fixup.c index dc1736bfc3ac2..aaac27d00590c 100644 --- a/drivers/gpu/drm/bridge/imx/imx8mp-hdmi-tx-connector-fixup.c +++ b/drivers/gpu/drm/bridge/imx/imx8mp-hdmi-tx-connector-fixup.c @@ -44,6 +44,23 @@ static int __init imx8mp_hdmi_tx_connector_fixup_init(void) if (endpoint) return 0; + /* + * Boards with an HDMI connector should describe it in a device + * tree node with compatible = "hdmi-connector". + * + * If you see this warning, it means such a node was not found and + * a fallback one is added using a device tree overlay. Please add + * one in your device tree, also describing the exact connector + * type (the added overlay assumes Type A as a fallback, but it + * might be wrong). + * + * This node is necessary for modern DRM, where bridge drivers do + * not create a connector (see the DRM_BRIDGE_ATTACH_NO_CONNECTOR + * flag). See https://docs.kernel.org/gpu/drm-kms-helpers.html for + * more info. + */ + pr_warn("Please add a hdmi-connector DT node for imx8mp-hdmi-tx.\n"); + dtbo_start = __dtbo_imx8mp_hdmi_tx_connector_fixup_begin; dtbo_size = __dtbo_imx8mp_hdmi_tx_connector_fixup_end - __dtbo_imx8mp_hdmi_tx_connector_fixup_begin; -- 2.47.3