[PATCH] drm/i915: Output a bit of debug info for display portbandwidth

[Keith Packard]

Something weird is going on with link bandwidth testing; this may
help sort out what's wrong.

Signed-off-by: Keith Packard <keithp@xxxxxxxxxx>
---
 drivers/gpu/drm/i915/intel_dp.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index db3b461..796d534 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -697,10 +697,13 @@ intel_dp_mode_fixup(struct drm_encoder *encoder, struct drm_display_mode *mode,
 		mode->clock = intel_dp->panel_fixed_mode->clock;
 	}
 
+	DRM_DEBUG_KMS("using bpp %d to find link_bw and lane_count\n", bpp);
 	for (lane_count = 1; lane_count <= max_lane_count; lane_count <<= 1) {
 		for (clock = 0; clock <= max_clock; clock++) {
 			int link_avail = intel_dp_max_data_rate(intel_dp_link_clock(bws[clock]), lane_count);
 
+			DRM_DEBUG_KMS("lane_count %d clock %d link_avail %d link_required %d\n",
+				      lane_count, clock, link_avail, intel_dp_link_required(intel_dp, mode->clock, bpp));
 			if (intel_dp_link_required(intel_dp, mode->clock, bpp)
 					<= link_avail) {
 				intel_dp->link_bw = bws[clock];
-- 
1.7.8.3


--__MailScanner_found_Cyrus_boundary_substring_problem__


Please try this on the broken kernel, sending along the dmesg output at
boot and resume time again.

-- 
keith.packard@xxxxxxxxx

--__MailScanner_found_Cyrus_boundary_substring_problem__--
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/