The patch below does not apply to the 4.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable@xxxxxxxxxxxxxxx>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From b36f7d26a7fdc0b07b1217368ee09bb8560269f8 Mon Sep 17 00:00:00 2001 From: Dave Airlie <airlied@xxxxxxxxxx> Date: Tue, 22 Mar 2016 09:38:18 +1000 Subject: [PATCH] drm/radeon/mst: fix regression in lane/link handling. The function this used changed in 092c96a8ab9d1bd60ada2ed385cc364ce084180e drm/radeon: fix dp link rate selection (v2) However for MST we should just always train to the max link/rate. Though we probably need to limit this for future hw, in theory radeon won't support it. This fixes my 30" monitor with MST enabled. Cc: stable@xxxxxxxxxxxxxxx # v4.4 Signed-off-by: Dave Airlie <airlied@xxxxxxxxxx> Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx> diff --git a/drivers/gpu/drm/radeon/radeon_dp_mst.c b/drivers/gpu/drm/radeon/radeon_dp_mst.c index df7a1719c841..9d210bbcab50 100644 --- a/drivers/gpu/drm/radeon/radeon_dp_mst.c +++ b/drivers/gpu/drm/radeon/radeon_dp_mst.c @@ -525,17 +525,9 @@ static bool radeon_mst_mode_fixup(struct drm_encoder *encoder, drm_mode_set_crtcinfo(adjusted_mode, 0); { struct radeon_connector_atom_dig *dig_connector; - int ret; - dig_connector = mst_enc->connector->con_priv; - ret = radeon_dp_get_dp_link_config(&mst_enc->connector->base, - dig_connector->dpcd, adjusted_mode->clock, - &dig_connector->dp_lane_count, - &dig_connector->dp_clock); - if (ret) { - dig_connector->dp_lane_count = 0; - dig_connector->dp_clock = 0; - } + dig_connector->dp_lane_count = drm_dp_max_lane_count(dig_connector->dpcd); + dig_connector->dp_clock = drm_dp_max_link_rate(dig_connector->dpcd); DRM_DEBUG_KMS("dig clock %p %d %d\n", dig_connector, dig_connector->dp_lane_count, dig_connector->dp_clock); } -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html