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<body><span class="vcard"><a class="email" href="mailto:ville.syrjala@linux.intel.com" title="Ville Syrjala <ville.syrjala@linux.intel.com>"> <span class="fn">Ville Syrjala</span></a>
</span> changed
<a class="bz_bug_link
bz_status_NEEDINFO "
title="NEEDINFO - Black/blank screen at boot (last message line: fb: switching to inteldrmfb from EFI VGA) unless i915.modeset=0 is set"
href="https://bugs.freedesktop.org/show_bug.cgi?id=105549">bug 105549</a>
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<th>What</th>
<th>Removed</th>
<th>Added</th>
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<td style="text-align:right;">Status</td>
<td>REOPENED
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<td>NEEDINFO
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<b><a class="bz_bug_link
bz_status_NEEDINFO "
title="NEEDINFO - Black/blank screen at boot (last message line: fb: switching to inteldrmfb from EFI VGA) unless i915.modeset=0 is set"
href="https://bugs.freedesktop.org/show_bug.cgi?id=105549#c19">Comment # 19</a>
on <a class="bz_bug_link
bz_status_NEEDINFO "
title="NEEDINFO - Black/blank screen at boot (last message line: fb: switching to inteldrmfb from EFI VGA) unless i915.modeset=0 is set"
href="https://bugs.freedesktop.org/show_bug.cgi?id=105549">bug 105549</a>
from <span class="vcard"><a class="email" href="mailto:ville.syrjala@linux.intel.com" title="Ville Syrjala <ville.syrjala@linux.intel.com>"> <span class="fn">Ville Syrjala</span></a>
</span></b>
<pre>[ 35.442022] [drm:intel_dp_init_connector [i915]] using AUX C for port C
(VBT)
[ 35.442038] [drm:intel_hdmi_init_connector [i915]] Adding HDMI connector on
port C
[ 35.442052] [drm:intel_hdmi_init_connector [i915]] Using DDC pin 0x2 for
port C (VBT)
...
[ 35.461411] WARN_ON(!intel_gmbus_is_valid_pin(dev_priv, pin))
...
[ 35.461609] BUG: unable to handle kernel NULL pointer dereference at
0000000000000010
[ 35.461613] IP: i2c_transfer+0x4/0x86
So the VBT has a bogus gmbus pin specified for some reason. 2==VGADDC and
indeed that doesn't appear in the skl valid pins list. And the spec agrees with
our list.
Please attach a copy of /sys/kernel/debug/dri/0/i915_vbt.
I wonder if we should perhaps reject the entire HDMI port when the gmbus pin is
bogus? We'd lose one the HDMI ports though. Also these machines seem to have
eDP + HDMI + DP via type-C + VGA on them. I wonder how it's all hooked up when
we have just three ports declared in the VBT...</pre>
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