Dell monitor with a built-in MST branch does not light up on boot when connected to a Thinkpad dock. The monitor also does not wake up after Suspend-to-Idle or dpms off in this configuration. Keeping the AUX powered up in the D3 power state solved this problem. This partially fixes Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=90963 Cc: Ethan Hsieh <ethan.hsieh@xxxxxxxxxxxxx> Cc: Lyude <cpaul@xxxxxxxxxx> Signed-off-by: Dhinakaran Pandiyan <dhinakaran.pandiyan@xxxxxxxxx> --- drivers/gpu/drm/i915/intel_dp.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c index 76c8a0b..5595367 100644 --- a/drivers/gpu/drm/i915/intel_dp.c +++ b/drivers/gpu/drm/i915/intel_dp.c @@ -2485,7 +2485,11 @@ void intel_dp_sink_dpms(struct intel_dp *intel_dp, int mode) return; if (mode != DRM_MODE_DPMS_ON) { - ret = drm_dp_dpcd_writeb(&intel_dp->aux, DP_SET_POWER, + if (intel_dp->is_mst) + ret = drm_dp_dpcd_writeb(&intel_dp->aux, DP_SET_POWER, + DP_SET_POWER_D3_AUX_ON); + else + ret = drm_dp_dpcd_writeb(&intel_dp->aux, DP_SET_POWER, DP_SET_POWER_D3); } else { struct intel_lspcon *lspcon = dp_to_lspcon(intel_dp); -- 2.7.4 _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel