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<base href="https://bugs.freedesktop.org/" />
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<th>Priority</th>
<td>medium
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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW --- - [Intel GM45][i915-kms]: VGA encoder on SDVOB remains blank when i915.ko is loaded while gfx is in text mode."
href="https://bugs.freedesktop.org/show_bug.cgi?id=63031">63031</a>
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<th>Assignee</th>
<td>intel-gfx-bugs@lists.freedesktop.org
</td>
</tr>
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<th>Summary</th>
<td>[Intel GM45][i915-kms]: VGA encoder on SDVOB remains blank when i915.ko is loaded while gfx is in text mode.
</td>
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<th>QA Contact</th>
<td>intel-gfx-bugs@lists.freedesktop.org
</td>
</tr>
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<th>Severity</th>
<td>normal
</td>
</tr>
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<th>Classification</th>
<td>Unclassified
</td>
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<th>OS</th>
<td>All
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<th>Reporter</th>
<td>eich@pdx.freedesktop.org
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<th>Hardware</th>
<td>x86-64 (AMD64)
</td>
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<th>Status</th>
<td>NEW
</td>
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<th>Version</th>
<td>XOrg CVS
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<th>Component</th>
<td>DRM/Intel
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<th>Product</th>
<td>DRI
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</tr></table>
<p>
<div>
<pre>With any latest Intel DRM kernels the VGA output on SDVOB remains dark when a
VGA text mode was set prior to loading the i915 driver.
When a VBE gfx mode was loaded, the system comes up fine.
Here is what happens:
When the driver loads intel_modeset_setup_hw_state() is called at one point to
collect the current state of the hardware setting.
At one point, this function calls into intel_sdvo_get_hw_state() to check if
bit 32 of register GEN3_SDVOB. If this bit is 0 the function returns 'false'
indicating there is no active pipe connected to this encoder.
intel_modeset_setup_hw_state() then calls intel_sanitize_encoder() which will
call intel_connector_break_all_links() in this situation.
At a later point intel_connector_check_state() will complain heavily.
As a result SDVOB will be treated as disabled and unconnected during the entire
mode setting.
Setting bit 31 of GEN3_SDVOB at any point before intel_modeset_setup_hw_state()
is called will cause the driver to correctly initialize the SDVOB.
Also setting a VBE gfx mode prior to loading the driver will set this bit and
thus the DAC encoder on SDVOB will be initialized correctly.
Thus the kernel is misled by a bogus mode set by the BIOS,</pre>
</div>
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