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<base href="https://bugs.freedesktop.org/">
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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - HDMI port not working on Intel® Skylake U SoC integrated Graphics"
href="https://bugs.freedesktop.org/show_bug.cgi?id=105056">105056</a>
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<th>Summary</th>
<td>HDMI port not working on Intel® Skylake U SoC integrated Graphics
</td>
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<th>Product</th>
<td>xorg
</td>
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<th>Version</th>
<td>unspecified
</td>
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<th>Hardware</th>
<td>Other
</td>
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<th>OS</th>
<td>All
</td>
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<th>Status</th>
<td>NEW
</td>
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<th>Severity</th>
<td>normal
</td>
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<th>Priority</th>
<td>medium
</td>
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<th>Component</th>
<td>Driver/intel
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<th>Assignee</th>
<td>chris@chris-wilson.co.uk
</td>
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<th>Reporter</th>
<td>e.deotto@gds.com
</td>
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<th>QA Contact</th>
<td>intel-gfx-bugs@lists.freedesktop.org
</td>
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<pre>Created <span class=""><a href="attachment.cgi?id=137291" name="attach_137291" title="output of dmesg">attachment 137291</a> <a href="attachment.cgi?id=137291&action=edit" title="output of dmesg">[details]</a></span>
output of dmesg
We are running Linux on a EMX-SKLUP machine
(<a href="https://www.avalue.com.tw/Product/Industrial-PC/Industrial-Motherboard/Thin-Mini-ITX/EMX-SKLUP_2521">https://www.avalue.com.tw/Product/Industrial-PC/Industrial-Motherboard/Thin-Mini-ITX/EMX-SKLUP_2521</a>
)
This machine mounts a graphics card: Intel® Skylake U SoC integrated Graphics
and we are using the i915 driver to drive two screens, one using the HDMI port
and the other using the DisplayPort.
We tried different kernels and we noticed the following:
1. Kernel 4.4 all versions work like a charm
2. Kernel 4.9 all versions before 4.9.30 work. All versions after 4.9.40
have problem with the HDMI port. It simply turns out to be always disconnected
when issuing an xrandr. Thus, the screen is simply blank. The DisplayPort
connection works perfectly.
We made some narrowing and the problem seems to have been introduced between
the following two commits:
• 4.9.30 commit:
<a href="https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git/commit/?h=linux-4.9.y&id=db3fd4527ed32be44cbd8ffa6dd6a301c89d0d6d">https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git/commit/?h=linux-4.9.y&id=db3fd4527ed32be44cbd8ffa6dd6a301c89d0d6d</a>
• 4.9.40 commit:
<a href="https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git/commit/?h=linux-4.9.y&id=efcfbfb1d8bf756d1b58fe215bf4e419d176435b">https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git/commit/?h=linux-4.9.y&id=efcfbfb1d8bf756d1b58fe215bf4e419d176435b</a>
• diff of i915 dir:
<a href="https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git/diff/drivers/gpu/drm/i915?h=linux-4.9.y&id=db3fd4527ed32be44cbd8ffa6dd6a301c89d0d6d&id2=efcfbfb1d8bf756d1b58fe215bf4e419d176435b">https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git/diff/drivers/gpu/drm/i915?h=linux-4.9.y&id=db3fd4527ed32be44cbd8ffa6dd6a301c89d0d6d&id2=efcfbfb1d8bf756d1b58fe215bf4e419d176435b</a>
3. All following kernels have the same problem.</pre>
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