From: jsg <jsg@openbsd.org>
Date: Fri, 8 Aug 2014 16:38:23 +0000 (+0000)
Subject: drm/radeon/dp: fix lane/clock setup for dp 1.2 capable devices
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=719013e9e0d572988467f815d6feb313daeca2b6;p=openbsd

drm/radeon/dp: fix lane/clock setup for dp 1.2 capable devices

From Alex Deucher
c9a1adc31f78a30f33c591b61171f02d13a5b1a7 in ubuntu 3.8
3b6d9fd23e015b5397c438fd3cd74147d2c805b6 in mainline linux
---

diff --git a/sys/dev/pci/drm/radeon/atombios_dp.c b/sys/dev/pci/drm/radeon/atombios_dp.c
index 59f14d71221..409d740752c 100644
--- a/sys/dev/pci/drm/radeon/atombios_dp.c
+++ b/sys/dev/pci/drm/radeon/atombios_dp.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: atombios_dp.c,v 1.3 2014/02/10 00:25:28 jsg Exp $	*/
+/*	$OpenBSD: atombios_dp.c,v 1.4 2014/08/08 16:38:23 jsg Exp $	*/
 /*
  * Copyright 2007-8 Advanced Micro Devices, Inc.
  * Copyright 2008 Red Hat Inc.
@@ -387,6 +387,19 @@ static int dp_get_max_dp_pix_clock(int link_rate,
 
 /***** radeon specific DP functions *****/
 
+static int radeon_dp_get_max_link_rate(struct drm_connector *connector,
+				       u8 dpcd[DP_DPCD_SIZE])
+{
+	int max_link_rate;
+
+	if (radeon_connector_is_dp12_capable(connector))
+		max_link_rate = min(drm_dp_max_link_rate(dpcd), 540000);
+	else
+		max_link_rate = min(drm_dp_max_link_rate(dpcd), 270000);
+
+	return max_link_rate;
+}
+
 /* First get the min lane# when low rate is used according to pixel clock
  * (prefer low rate), second check max lane# supported by DP panel,
  * if the max lane# < low rate lane# then use max lane# instead.
@@ -396,7 +409,7 @@ static int radeon_dp_get_dp_lane_number(struct drm_connector *connector,
 					int pix_clock)
 {
 	int bpp = convert_bpc_to_bpp(radeon_get_monitor_bpc(connector));
-	int max_link_rate = drm_dp_max_link_rate(dpcd);
+	int max_link_rate = radeon_dp_get_max_link_rate(connector, dpcd);
 	int max_lane_num = drm_dp_max_lane_count(dpcd);
 	int lane_num;
 	int max_dp_pix_clock;
@@ -434,7 +447,7 @@ static int radeon_dp_get_dp_link_clock(struct drm_connector *connector,
 			return 540000;
 	}
 
-	return drm_dp_max_link_rate(dpcd);
+	return radeon_dp_get_max_link_rate(connector, dpcd);
 }
 
 static u8 radeon_dp_encoder_service(struct radeon_device *rdev,