[Bug 103400] [KBL] Black screen at boot, unknown DP link BW code 0 warning

[bugzilla-daemon at freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=103400

Jani Nikula <jani.nikula at intel.com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |NEEDINFO

--- Comment #1 from Jani Nikula <jani.nikula at intel.com> ---
I think the problem is that your display has incorrect eDP DPCD information
(bit 3 of DPCD register 0x006 is not set, instead the whole register is set to
0x03). Please try this debug patch to see if it helps:

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index aa75f55eeb61..b2bb7d2941f3 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -3736,8 +3736,7 @@ intel_edp_init_dpcd(struct intel_dp *intel_dp)
        }

        /* Read the eDP Display control capabilities registers */
-       if ((intel_dp->dpcd[DP_EDP_CONFIGURATION_CAP] &
DP_DPCD_DISPLAY_CONTROL_CAPABLE) &&
-           drm_dp_dpcd_read(&intel_dp->aux, DP_EDP_DPCD_REV,
+       if (drm_dp_dpcd_read(&intel_dp->aux, DP_EDP_DPCD_REV,
                             intel_dp->edp_dpcd, sizeof(intel_dp->edp_dpcd)) ==
                             sizeof(intel_dp->edp_dpcd))
                DRM_DEBUG_KMS("EDP DPCD : %*ph\n", (int)
sizeof(intel_dp->edp_dpcd),

Please let us know the contents of that "EDP DPCD" debug message with this
change.

-- 
You are receiving this mail because:
You are the assignee for the bug.
You are the QA Contact for the bug.
You are on the CC list for the bug.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.freedesktop.org/archives/intel-gfx-bugs/attachments/20171025/fab78d8a/attachment.html>