[PATCH] drm/i915/dp: Allow for 5.4Gbps for Haswell.

[Carl Worth]

With Haswell, 5.4Gbps is supported. And almost all of the code was
already in place already. All that was missing was this tiny bit of
additional wiring.

Signed-off-by: Carl Worth <cworth at cworth.org>
Reviewed-by: Keith Packard <keithp at keithp.com>
---
 drivers/gpu/drm/i915/intel_dp.c | 24 ++++++++++++++++++++----
 1 file changed, 20 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 57552eb..ce9739e 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -101,7 +101,11 @@ intel_dp_max_link_bw(struct intel_dp *intel_dp)
 	case DP_LINK_BW_1_62:
 	case DP_LINK_BW_2_7:
 		break;
-	case DP_LINK_BW_5_4: /* 1.2 capable displays may advertise higher bw */
+	case DP_LINK_BW_5_4:
+		/* XXX: But not HASWELL ULX. */
+		if (IS_HASWELL(intel_dp_to_dev(intel_dp)))
+			break;
+		/* Prior to HASWELL, maximum support is for 2.7 Gbps */
 		max_link_bw = DP_LINK_BW_2_7;
 		break;
 	default:
@@ -810,12 +814,24 @@ intel_dp_compute_config(struct intel_encoder *encoder,
 	enum port port = dp_to_dig_port(intel_dp)->port;
 	struct intel_crtc *intel_crtc = encoder->new_crtc;
 	struct intel_connector *intel_connector = intel_dp->attached_connector;
-	int lane_count, clock;
+	int lane_count;
 	int max_lane_count = drm_dp_max_lane_count(intel_dp->dpcd);
-	int max_clock = intel_dp_max_link_bw(intel_dp) == DP_LINK_BW_2_7 ? 1 : 0;
 	int bpp, mode_rate;
-	static int bws[2] = { DP_LINK_BW_1_62, DP_LINK_BW_2_7 };
 	int link_avail, link_clock;
+	int max_link_bw;
+	/* The clock and max_clock values are an index into bws. */
+	int clock, max_clock = 0;
+	static int bws[3] = { DP_LINK_BW_1_62, DP_LINK_BW_2_7, DP_LINK_BW_5_4};
+
+	max_link_bw = intel_dp_max_link_bw(intel_dp);
+
+	for (clock = 0; clock < ARRAY_SIZE(bws); clock++) {
+		if (bws[clock] == max_link_bw) {
+			max_clock = clock;
+			break;
+		}
+	}
+
 
 	if (HAS_PCH_SPLIT(dev) && !HAS_DDI(dev) && port != PORT_A)
 		pipe_config->has_pch_encoder = true;
-- 
1.9.0