From edb39244fad2e96ba03ea97a4b2c585c7f2fc7e4 Mon Sep 17 00:00:00 2001
From: Adam Jackson <ajax@redhat.com>
Date: Tue, 18 Sep 2012 10:58:49 -0400
Subject: drm/i915/dp: Fetch downstream port info if needed during DPCD fetch
Git-commit: edb39244fad2e96ba03ea97a4b2c585c7f2fc7e4
Patch-mainline: v3.7-rc3

v2: Fix parenthesis mismatch, spotted by Jani Nikula

Tested-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Adam Jackson <ajax@redhat.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
[danvet: Fixup merge conflict and MAX_DOWNSTREAM #define as spotted by
Jani.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Michal Srb <msrb@suse.com>
---
 drivers/gpu/drm/i915/intel_dp.c  |   24 +++++++++++++++++++-----
 drivers/gpu/drm/i915/intel_drv.h |    2 ++
 2 files changed, 21 insertions(+), 5 deletions(-)

Index: linux-3.0-SLE11-SP3/drivers/gpu/drm/i915/intel_dp.c
===================================================================
--- linux-3.0-SLE11-SP3.orig/drivers/gpu/drm/i915/intel_dp.c
+++ linux-3.0-SLE11-SP3/drivers/gpu/drm/i915/intel_dp.c
@@ -36,6 +36,7 @@
 #include "i915_drm.h"
 #include "i915_drv.h"
 
+#define DP_RECEIVER_CAP_SIZE	0xf
 #define DP_LINK_STATUS_SIZE	6
 #define DP_LINK_CHECK_TIMEOUT	(10 * 1000)
 
@@ -1963,12 +1964,25 @@ static bool
 intel_dp_get_dpcd(struct intel_dp *intel_dp)
 {
 	if (intel_dp_aux_native_read_retry(intel_dp, 0x000, intel_dp->dpcd,
-					   sizeof (intel_dp->dpcd)) &&
-	    (intel_dp->dpcd[DP_DPCD_REV] != 0)) {
-		return true;
-	}
+					   sizeof(intel_dp->dpcd)) == 0)
+		return false; /* aux transfer failed */
 
-	return false;
+	if (intel_dp->dpcd[DP_DPCD_REV] == 0)
+		return false; /* DPCD not present */
+
+	if (!(intel_dp->dpcd[DP_DOWNSTREAMPORT_PRESENT] &
+	      DP_DWN_STRM_PORT_PRESENT))
+		return true; /* native DP sink */
+
+	if (intel_dp->dpcd[DP_DPCD_REV] == 0x10)
+		return true; /* no per-port downstream info */
+
+	if (intel_dp_aux_native_read_retry(intel_dp, DP_DOWNSTREAM_PORT_0,
+					   intel_dp->downstream_ports,
+					   DP_MAX_DOWNSTREAM_PORTS) == 0)
+		return false; /* downstream port status fetch failed */
+
+	return true;
 }
 
 static void
Index: linux-3.0-SLE11-SP3/drivers/gpu/drm/i915/intel_drv.h
===================================================================
--- linux-3.0-SLE11-SP3.orig/drivers/gpu/drm/i915/intel_drv.h
+++ linux-3.0-SLE11-SP3/drivers/gpu/drm/i915/intel_drv.h
@@ -332,6 +332,7 @@ struct intel_hdmi {
 };
 
 #define DP_RECEIVER_CAP_SIZE		0xf
+#define DP_MAX_DOWNSTREAM_PORTS		0x10
 #define DP_LINK_CONFIGURATION_SIZE	9
 
 struct intel_dp {
@@ -346,6 +347,7 @@ struct intel_dp {
 	uint8_t link_bw;
 	uint8_t lane_count;
 	uint8_t dpcd[DP_RECEIVER_CAP_SIZE];
+	uint8_t downstream_ports[DP_MAX_DOWNSTREAM_PORTS];
 	struct i2c_adapter adapter;
 	struct i2c_algo_dp_aux_data algo;
 	bool is_pch_edp;
