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<body><span class="vcard"><a class="email" href="mailto:jani.nikula@intel.com" title="Jani Nikula <jani.nikula@intel.com>"> <span class="fn">Jani Nikula</span></a>
</span> changed
<a class="bz_bug_link
bz_status_NEEDINFO "
title="NEEDINFO - [KBL] Black screen at boot, unknown DP link BW code 0 warning"
href="https://bugs.freedesktop.org/show_bug.cgi?id=103400">bug 103400</a>
<br>
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<tr>
<th>What</th>
<th>Removed</th>
<th>Added</th>
</tr>
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<td style="text-align:right;">Status</td>
<td>NEW
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<td>NEEDINFO
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<b><a class="bz_bug_link
bz_status_NEEDINFO "
title="NEEDINFO - [KBL] Black screen at boot, unknown DP link BW code 0 warning"
href="https://bugs.freedesktop.org/show_bug.cgi?id=103400#c1">Comment # 1</a>
on <a class="bz_bug_link
bz_status_NEEDINFO "
title="NEEDINFO - [KBL] Black screen at boot, unknown DP link BW code 0 warning"
href="https://bugs.freedesktop.org/show_bug.cgi?id=103400">bug 103400</a>
from <span class="vcard"><a class="email" href="mailto:jani.nikula@intel.com" title="Jani Nikula <jani.nikula@intel.com>"> <span class="fn">Jani Nikula</span></a>
</span></b>
<pre>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.</pre>
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