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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - [DRM/i915][Bisected] Kernel panic in setup_vector_irq() with HDMI LPE driver while putting offline CPU thread back to online"
href="https://bugs.freedesktop.org/show_bug.cgi?id=103731">103731</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>[DRM/i915][Bisected] Kernel panic in setup_vector_irq() with HDMI LPE driver while putting offline CPU thread back to online
</td>
</tr>
<tr>
<th>Product</th>
<td>DRI
</td>
</tr>
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<th>Version</th>
<td>XOrg git
</td>
</tr>
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<th>Hardware</th>
<td>x86-64 (AMD64)
</td>
</tr>
<tr>
<th>OS</th>
<td>Linux (All)
</td>
</tr>
<tr>
<th>Status</th>
<td>NEW
</td>
</tr>
<tr>
<th>Severity</th>
<td>major
</td>
</tr>
<tr>
<th>Priority</th>
<td>high
</td>
</tr>
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<th>Component</th>
<td>DRM/Intel
</td>
</tr>
<tr>
<th>Assignee</th>
<td>intel-gfx-bugs@lists.freedesktop.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>augustine.chen@intel.com
</td>
</tr>
<tr>
<th>QA Contact</th>
<td>intel-gfx-bugs@lists.freedesktop.org
</td>
</tr>
<tr>
<th>CC</th>
<td>intel-gfx-bugs@lists.freedesktop.org
</td>
</tr>
<tr>
<th>i915 platform</th>
<td>BSW/CHT
</td>
</tr>
<tr>
<th>i915 features</th>
<td>display/audio
</td>
</tr></table>
<p>
<div>
<pre>Created <span class=""><a href="attachment.cgi?id=135445" name="attach_135445" title="Full dmesg">attachment 135445</a> <a href="attachment.cgi?id=135445&action=edit" title="Full dmesg">[details]</a></span>
Full dmesg
System Environment:
--------------------------
-- Platform: CHT
-- System architecture: x86_64
-- Kernel version: 4.14.0-041400-generic
-- Linux distribution: Ubuntu 16.04 LTS
-- Mother board model: CHT T3 RVP with CHT-T3 D1 SOC (both T3 and T4 RVPs are
reproducible)
-- Display connector: HDMI
Bug detailed description:
-----------------------------
While doing CPU thread online/offline test, the system hanging could be
observed when putting offline thread back to online. This issue is reproducible
since Kernel 4.11-rc1 and is still present in Kernel 4.14. This issue had been
bisected to happen since this commit eef57324d926f0d8c7a40069e7d26e0cb0651b47.
And after digging further, Kernel panic in setup_vector_irq() with debug
messages as below could be captured.
------------[ cut here ]------------
[ 87.353072] irq 298 idata->chip->name hdmi_lpe_audio_irqchip
[ 87.353072] irq 298 apic_chip_data
[ 87.353073] irq 298 data->domain is NULL
[ 87.353120] BUG: unable to handle kernel NULL pointer dereference at (null)
[ 87.353132] IP: setup_vector_irq+0x1ba/0x230
[ 87.353133] PGD 0
Reproduce steps:
----------------------------
1. check cpuinfo $ grep "processor" /proc/cpuinfo
2. disable cpu[1-3] $ echo 0 > /sys/devices/system/cpu/cpu[1-3]/online
3. enable cpu[1-3] $ echo 1 > /sys/devices/system/cpu/cpu[1-3]/online <-- issue
happens, system hangs.
First bad commit:
----------------------------
commit eef57324d926f0d8c7a40069e7d26e0cb0651b47</pre>
</div>
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