drm/i915/dp: Allow for 5.4Gbps for Haswell.

Commit Message

Carl Worth Feb. 27, 2014, 8:11 a.m. UTC

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 <[e-mail]>
Reviewed-by: Keith Packard <[e-mail]>
---
 drivers/gpu/drm/i915/intel_dp.c | 24 ++++++++++++++++++++----
 1 file changed, 20 insertions(+), 4 deletions(-)

Comments

Ville Syrjala Feb. 27, 2014, 8:49 a.m. UTC | #1

On Thu, Feb 27, 2014 at 12:11:39AM -0800, Carl Worth wrote:
> 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.

Todd already implemented 5.4Gbps support a while back. So it seems your
tree is a bit out of date.

Keith Packard Feb. 27, 2014, 6:21 p.m. UTC | #2

Ville Syrjälä <[e-mail]> writes:

> Todd already implemented 5.4Gbps support a while back. So it seems your
> tree is a bit out of date.

I didn't find it on drm-intel-fixes-2014-02-14; can you explain which
tree it is present in?

Paulo Zanoni Feb. 27, 2014, 6:29 p.m. UTC | #3

2014-02-27 15:21 GMT-03:00 Keith Packard <[e-mail]>:
> Ville Syrjälä <[e-mail]> writes:
>
>> Todd already implemented 5.4Gbps support a while back. So it seems your
>> tree is a bit out of date.
>
> I didn't find it on drm-intel-fixes-2014-02-14; can you explain which
> tree it is present in?

It's on the drm-intel-next-queued branch. Please notice we recently
moved the tree from freedesktop.org/~danvet/drm-intel to
freedesktop.org/drm-intel.

http://cgit.freedesktop.org/drm-intel/commit/?h=drm-intel-next-queued&id=06ea66b6bb445043dc25a9626254d5c130093199


>
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>
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>

Patch

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;