diff --git a/drivers/gpu/drm/xlnx/zynqmp_dp.c b/drivers/gpu/drm/xlnx/zynqmp_dp.c index 28f92b5d8385d..0aa810ebdecaf 100644 --- a/drivers/gpu/drm/xlnx/zynqmp_dp.c +++ b/drivers/gpu/drm/xlnx/zynqmp_dp.c @@ -283,6 +283,7 @@ struct zynqmp_dp_config { * @reset: reset controller * @irq: irq * @bridge: DRM bridge for the DP encoder + * @next_bridge: The downstream bridge * @config: IP core configuration from DTS * @aux: aux channel * @phy: PHY handles for DP lanes @@ -305,6 +306,7 @@ struct zynqmp_dp { int irq; struct drm_bridge bridge; + struct drm_bridge *next_bridge; struct zynqmp_dp_config config; struct drm_dp_aux aux; @@ -1307,6 +1309,13 @@ static int zynqmp_dp_bridge_attach(struct drm_bridge *bridge, drm_connector_register(connector); drm_connector_attach_encoder(connector, bridge->encoder); + if (dp->next_bridge) { + ret = drm_bridge_attach(bridge->encoder, dp->next_bridge, + bridge, DRM_BRIDGE_ATTACH_NO_CONNECTOR); + if (ret < 0) + return ret; + } + return 0; } @@ -1744,6 +1753,15 @@ int zynqmp_dp_probe(struct zynqmp_dpsub *dpsub, struct drm_device *drm) if (ret) goto err_reset; + /* + * Acquire the next bridge in the chain. Ignore errors caused by port@5 + * not being connected for backward-compatibility with older DTs. + */ + ret = drm_of_find_panel_or_bridge(dp->dev->of_node, 5, 0, NULL, + &dp->next_bridge); + if (ret < 0 && ret != -ENODEV) + goto err_reset; + /* Initialize the hardware. */ zynqmp_dp_write(dp, ZYNQMP_DP_TX_PHY_POWER_DOWN, ZYNQMP_DP_TX_PHY_POWER_DOWN_ALL);