drm/i915/dp: Dump DP link status when link training stages fail

A full dump of link status can be handy in debugging link training
failures. Let's add that to the debug messages when link training fails.

v2: Removing unrelated clean up (Jani)
Signed-off-by: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1470343716-5574-3-git-send-email-dhinakaran.pandiyan@intel.com

diff --git a/drivers/gpu/drm/i915/intel_dp_link_training.c b/drivers/gpu/drm/i915/intel_dp_link_training.c
index 60fb39cd220b4a01f5b9469a5de29ee496abe61f..0deebed71a26d824ebf8c5770b28e704f38bed1c 100644 (file)
--- a/drivers/gpu/drm/i915/intel_dp_link_training.c
+++ b/drivers/gpu/drm/i915/intel_dp_link_training.c
@@ -23,6 +23,15 @@
 
 #include "intel_drv.h"
 
+static void
+intel_dp_dump_link_status(const uint8_t link_status[DP_LINK_STATUS_SIZE])
+{
+
+       DRM_DEBUG_KMS("ln0_1:0x%x ln2_3:0x%x align:0x%x sink:0x%x adj_req0_1:0x%x adj_req2_3:0x%x",
+                     link_status[0], link_status[1], link_status[2],
+                     link_status[3], link_status[4], link_status[5]);
+}
+
 static void
 intel_get_adjust_train(struct intel_dp *intel_dp,
                       const uint8_t link_status[DP_LINK_STATUS_SIZE])
@@ -168,6 +177,7 @@ intel_dp_link_training_clock_recovery(struct intel_dp *intel_dp)
                        ++loop_tries;
                        if (loop_tries == 5) {
                                DRM_ERROR("too many full retries, give up\n");
+                               intel_dp_dump_link_status(link_status);
                                break;
                        }
                        intel_dp_reset_link_train(intel_dp,
@@ -254,6 +264,7 @@ intel_dp_link_training_channel_equalization(struct intel_dp *intel_dp)
 
                if (cr_tries > 5) {
                        DRM_ERROR("failed to train DP, aborting\n");
+                       intel_dp_dump_link_status(link_status);
                        break;
                }