From: Tomi Valkeinen Date: Wed, 8 Nov 2023 11:27:23 +0000 (+0200) Subject: drm/bridge: tc358767: Fix link properties discovery X-Git-Tag: microblaze-v6.16~14^2~23^2~275 X-Git-Url: http://git.monstr.eu/?a=commitdiff_plain;h=2d343723c7e1f9f6d64f721f07cfdfc2993758d1;p=linux-2.6-microblaze.git drm/bridge: tc358767: Fix link properties discovery When a display controller driver uses DRM_BRIDGE_ATTACH_NO_CONNECTOR, tc358767 will behave properly and skip the creation of the connector. However, tc_get_display_props(), which is used to find out about the DP monitor and link, is only called from two places: .atomic_enable() and tc_connector_get_modes(). The latter is only used when tc358767 creates its own connector, i.e. when DRM_BRIDGE_ATTACH_NO_CONNECTOR is _not_ set. Thus, the driver never finds out the link properties before get_edid() is called. With num_lanes of 0 and link_rate of 0 there are not many valid modes... Fix this by adding tc_get_display_props() call at the beginning of get_edid(), so that we have up to date information before looking at the modes. Reported-by: Jan Kiszka Closes: https://lore.kernel.org/all/24282420-b4dd-45b3-bb1c-fc37fe4a8205@siemens.com/ Fixes: de5e6c027ae6 ("drm/bridge: tc358767: add drm_panel_bridge support") Reviewed-by: Aradhya Bhatia Tested-by: Jan Kiszka Signed-off-by: Tomi Valkeinen Link: https://patchwork.freedesktop.org/patch/msgid/20231108-tc358767-v2-2-25c5f70a2159@ideasonboard.com Signed-off-by: Dmitry Baryshkov --- diff --git a/drivers/gpu/drm/bridge/tc358767.c b/drivers/gpu/drm/bridge/tc358767.c index 159c95b26d33..0c48e747f5b0 100644 --- a/drivers/gpu/drm/bridge/tc358767.c +++ b/drivers/gpu/drm/bridge/tc358767.c @@ -1714,6 +1714,13 @@ static const struct drm_edid *tc_edid_read(struct drm_bridge *bridge, struct drm_connector *connector) { struct tc_data *tc = bridge_to_tc(bridge); + int ret; + + ret = tc_get_display_props(tc); + if (ret < 0) { + dev_err(tc->dev, "failed to read display props: %d\n", ret); + return 0; + } return drm_edid_read_ddc(connector, &tc->aux.ddc); }