From 6e1f8557818f3c2476404ba1d4a5157b823b79f0 Mon Sep 17 00:00:00 2001 From: Laurent Pinchart Date: Thu, 17 Jan 2019 00:43:08 +0200 Subject: [PATCH] drm: rcar-du: lvds: Don't fail probe if output is not connected on D3/E3 On the D3 and E3 SoCs the LVDS encoder has an extended internal PLL and supplies a clock to the DU. That clock is used not only for the LVDS outputs but also for the DPAD output. The LVDS encoder thus needs to be available to the DU even when its output is disabled. Don't fail probe in that case on D3 and E3. Signed-off-by: Laurent Pinchart --- drivers/gpu/drm/rcar-du/rcar_lvds.c | 17 +++++++++++++++-- 1 file changed, 15 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/rcar-du/rcar_lvds.c b/drivers/gpu/drm/rcar-du/rcar_lvds.c index 997927e8b0b6..a7789c5b3880 100644 --- a/drivers/gpu/drm/rcar-du/rcar_lvds.c +++ b/drivers/gpu/drm/rcar-du/rcar_lvds.c @@ -545,7 +545,10 @@ static int rcar_lvds_attach(struct drm_bridge *bridge) return drm_bridge_attach(bridge->encoder, lvds->next_bridge, bridge); - /* Otherwise we have a panel, create a connector. */ + /* Otherwise if we have a panel, create a connector. */ + if (!lvds->panel) + return 0; + ret = drm_connector_init(bridge->dev, connector, &rcar_lvds_conn_funcs, DRM_MODE_CONNECTOR_LVDS); if (ret < 0) @@ -593,7 +596,8 @@ static int rcar_lvds_parse_dt(struct rcar_lvds *lvds) local_output = of_graph_get_endpoint_by_regs(lvds->dev->of_node, 1, 0); if (!local_output) { dev_dbg(lvds->dev, "unconnected port@1\n"); - return -ENODEV; + ret = -ENODEV; + goto done; } /* @@ -643,6 +647,15 @@ done: of_node_put(remote_input); of_node_put(remote); + /* + * On D3/E3 the LVDS encoder provides a clock to the DU, which can be + * used for the DPAD output even when the LVDS output is not connected. + * Don't fail probe in that case as the DU will need the bridge to + * control the clock. + */ + if (lvds->info->quirks & RCAR_LVDS_QUIRK_EXT_PLL) + return ret == -ENODEV ? 0 : ret; + return ret; } -- 2.30.2