From 43072a454646d22f81808bdc8fb1b269ee1717a6 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Ville=20Syrj=C3=A4l=C3=A4?= Date: Mon, 18 Aug 2014 22:16:07 +0300 Subject: [PATCH] drm/i915: Turn on panel power before doing aux transfers MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit On VLV/CHV the panel power sequencer may need to be "kicked" a bit to lock onto the new port, and that needs to happen before any aux transfers are attempted if we want the aux transfers to actaully succeed. So turn on panel power (part of the "kick") before aux transfers (DPMS_ON + link training). This also matches the documented modeset sequence better for pch platforms. The documentation doesn't explicitly state anything about the DPMS or link training DPCD writes, but the panel power on step is always listed before link training is mentioned. Signed-off-by: Ville Syrjälä Reviewed-by: Imre Deak References: https://bugs.freedesktop.org/show_bug.cgi?id=70117 Signed-off-by: Daniel Vetter --- drivers/gpu/drm/i915/intel_dp.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c index b036465e3aa2..8935c5113ea7 100644 --- a/drivers/gpu/drm/i915/intel_dp.c +++ b/drivers/gpu/drm/i915/intel_dp.c @@ -2374,10 +2374,10 @@ static void intel_enable_dp(struct intel_encoder *encoder) return; intel_edp_panel_vdd_on(intel_dp); - intel_dp_sink_dpms(intel_dp, DRM_MODE_DPMS_ON); - intel_dp_start_link_train(intel_dp); intel_edp_panel_on(intel_dp); intel_edp_panel_vdd_off(intel_dp, true); + intel_dp_sink_dpms(intel_dp, DRM_MODE_DPMS_ON); + intel_dp_start_link_train(intel_dp); intel_dp_complete_link_train(intel_dp); intel_dp_stop_link_train(intel_dp); } -- 2.20.1