[Intel-gfx] [PATCH v3 2/6] drm/i915: Remove the link rate and lane count loop in compute config

[Manasi Navare]

While configuring the pipe during modeset, it should use
max clock and max lane count and reduce the bpp until
the requested mode rate is less than or equal to
available link BW.
This is required to pass DP Compliance.

v3:
* Add Debug print if requested mode cannot be supported
during modeset (Dhinakaran Pandiyan)
v2:
* Removed the loop since we use max values of clock
and lane count (Dhinakaran Pandiyan)

Signed-off-by: Manasi Navare <manasi.d.navare at intel.com>
---
 drivers/gpu/drm/i915/intel_dp.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index d81c67cb..65b4559 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -1644,23 +1644,17 @@ intel_dp_compute_config(struct intel_encoder *encoder,
 	for (; bpp >= 6*3; bpp -= 2*3) {
 		mode_rate = intel_dp_link_required(adjusted_mode->crtc_clock,
 						   bpp);
+		clock = max_clock;
+		lane_count = max_lane_count;
+		link_clock = common_rates[clock];
+		link_avail = intel_dp_max_data_rate(link_clock,
+						    lane_count);
 
-		for (clock = min_clock; clock <= max_clock; clock++) {
-			for (lane_count = min_lane_count;
-				lane_count <= max_lane_count;
-				lane_count <<= 1) {
-
-				link_clock = common_rates[clock];
-				link_avail = intel_dp_max_data_rate(link_clock,
-								    lane_count);
-
-				if (mode_rate <= link_avail) {
-					goto found;
-				}
-			}
-		}
+		if (mode_rate <= link_avail)
+			goto found;
 	}
 
+	DRM_DEBUG_KMS("Requested Mode Rate not supported\n");
 	return false;
 
 found:
-- 
1.9.1