From: Ville Syrjälä Date: Wed, 26 Oct 2016 09:05:55 +0000 (+0300) Subject: drm/dp/mst: Check peer device type before attempting EDID read X-Git-Tag: firefly_0821_release~176^2~4^2~19^2~17 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=9702108e3def0fca8fe47949270a97e18f1e4e50;p=firefly-linux-kernel-4.4.55.git drm/dp/mst: Check peer device type before attempting EDID read commit 4da5caa6a6f82cda3193bca855235b87debf78bd upstream. Only certain types of pdts have the DDC bus registered, so check for that before we attempt the EDID read. Othwewise we risk playing around with an i2c adapter that doesn't actually exist. Cc: Carlos Santa Cc: Kirill A. Shutemov Tested-by: Carlos Santa Tested-by: Kirill A. Shutemov Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=97666 Signed-off-by: Ville Syrjälä Signed-off-by: Daniel Vetter Link: http://patchwork.freedesktop.org/patch/msgid/1477472755-15288-5-git-send-email-ville.syrjala@linux.intel.com Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c index 528ef43a6ad9..7cb2815e815e 100644 --- a/drivers/gpu/drm/drm_dp_mst_topology.c +++ b/drivers/gpu/drm/drm_dp_mst_topology.c @@ -1155,7 +1155,9 @@ static void drm_dp_add_port(struct drm_dp_mst_branch *mstb, drm_dp_put_port(port); goto out; } - if (port->port_num >= DP_MST_LOGICAL_PORT_0) { + if ((port->pdt == DP_PEER_DEVICE_DP_LEGACY_CONV || + port->pdt == DP_PEER_DEVICE_SST_SINK) && + port->port_num >= DP_MST_LOGICAL_PORT_0) { port->cached_edid = drm_get_edid(port->connector, &port->aux.ddc); drm_mode_connector_set_tile_property(port->connector); }