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<base href="https://bugs.freedesktop.org/">
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<body><table border="1" cellspacing="0" cellpadding="8">
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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - DP-1 display panel can't be used"
href="https://bugs.freedesktop.org/show_bug.cgi?id=104184">104184</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>DP-1 display panel can't be used
</td>
</tr>
<tr>
<th>Product</th>
<td>DRI
</td>
</tr>
<tr>
<th>Version</th>
<td>unspecified
</td>
</tr>
<tr>
<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>normal
</td>
</tr>
<tr>
<th>Priority</th>
<td>medium
</td>
</tr>
<tr>
<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>robsmithy@gmail.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></table>
<p>
<div>
<pre>Created <span class=""><a href="attachment.cgi?id=136059" name="attach_136059" title="journalctl output filtered for kernel or drm">attachment 136059</a> <a href="attachment.cgi?id=136059&action=edit" title="journalctl output filtered for kernel or drm">[details]</a></span>
journalctl output filtered for kernel or drm
Unable to enable the outer/top screen of Asus Taichi laptop (TAICHI21 variant,
Ivy bridge/HD4000 integrated graphics) with the i915 driver on Ubuntu 17.10.
This worked previously (Ubuntu 16.x) as long as the laptop was booted with the
lid closed (see background below). The Taichi has 2 screens, 1 on the outside
of the lid and one on the underside. To use the Taichi as a tablet, one closes
the lid and uses the outer (touch)screen. Opening the lid should switch off the
outer screen so that the Taichi acts as a normal laptop using the screen on the
underside.
With drm.debug verbose output turned on, the following warnings appear
(summary/headers here, the kernel/drm related journalctl output is attached):
Dec 09 20:44:45 ras-TAICHI kernel: WARN_ON(len <= 0)
Dec 09 20:44:45 ras-TAICHI kernel: WARNING: CPU: 3 PID: 211 at
/home/kernel/COD/linux/drivers/gpu/drm/i915/intel_dp.c:1539
intel_dp_max_link_rate+0x5e/0x80 [i915]
Dec 09 20:44:45 ras-TAICHI kernel: WARN_ON(len <= 0)
Dec 09 20:44:45 ras-TAICHI kernel: WARNING: CPU: 3 PID: 211 at
/home/kernel/COD/linux/drivers/gpu/drm/i915/intel_dp.c:1539
intel_dp_max_link_rate+0x5e/0x80 [i915]
Dec 09 20:44:45 ras-TAICHI kernel: WARN_ON(common_len <= 0)
Dec 09 20:44:45 ras-TAICHI kernel: WARNING: CPU: 3 PID: 211 at
/home/kernel/COD/linux/drivers/gpu/drm/i915/intel_dp.c:1638
intel_dp_compute_config+0xf1/0x990 [i915]
Dec 09 20:44:45 ras-TAICHI kernel: WARN_ON(common_len <= 0)
Dec 09 20:44:45 ras-TAICHI kernel: WARNING: CPU: 3 PID: 211 at
/home/kernel/COD/linux/drivers/gpu/drm/i915/intel_dp.c:1638
intel_dp_compute_config+0xf1/0x990 [i915]
Dec 09 20:44:45 ras-TAICHI kernel: WARN_ON(len <= 0)
... <truncated, these warnings repeat>
Accompanied by the following errors:
Dec 09 20:44:45 ras-TAICHI kernel: [drm:intel_crt_get_edid [i915]] CRT GMBUS
EDID read failed, retry using GPIO bit-banging
Dec 09 20:44:45 ras-TAICHI kernel: [drm:intel_atomic_check.part.134 [i915]]
Encoder config failure
Dec 09 20:44:45 ras-TAICHI kernel: [drm:intel_dump_pipe_config [i915]]
[CRTC:37:pipe A][failed]
Dec 09 20:44:45 ras-TAICHI kernel: [drm:intel_atomic_check.part.134 [i915]]
Encoder config failure
Dec 09 20:44:45 ras-TAICHI kernel: [drm:intel_dump_pipe_config [i915]]
[CRTC:37:pipe A][failed]
Dec 09 20:44:45 ras-TAICHI kernel: [drm:intel_crt_get_edid [i915]] CRT GMBUS
EDID read failed, retry using GPIO bit-banging
Dec 09 20:44:45 ras-TAICHI kernel: [drm:intel_atomic_check.part.134 [i915]]
Encoder config failure
Dec 09 20:44:45 ras-TAICHI kernel: [drm:intel_dump_pipe_config [i915]]
[CRTC:37:pipe A][failed]
Dec 09 20:44:45 ras-TAICHI kernel: [drm:intel_crt_get_edid [i915]] CRT GMBUS
EDID read failed, retry using GPIO bit-banging
Dec 09 20:44:45 ras-TAICHI kernel: [drm:intel_atomic_check.part.134 [i915]]
Encoder config failure
Dec 09 20:44:45 ras-TAICHI kernel: [drm:intel_dump_pipe_config [i915]]
[CRTC:37:pipe A][failed]
Dec 09 20:44:45 ras-TAICHI kernel: [drm:intel_atomic_check.part.134 [i915]]
Encoder config failure
Dec 09 20:44:45 ras-TAICHI kernel: [drm:intel_dump_pipe_config [i915]]
[CRTC:37:pipe A][failed]
Dec 09 20:44:45 ras-TAICHI kernel: [drm:intel_crt_get_edid [i915]] CRT GMBUS
EDID read failed, retry using GPIO bit-banging
Dec 09 20:44:45 ras-TAICHI kernel: [drm:intel_atomic_check.part.134 [i915]]
Encoder config failure
Dec 09 20:44:45 ras-TAICHI kernel: [drm:intel_dump_pipe_config [i915]]
[CRTC:37:pipe A][failed]
Dec 09 20:44:45 ras-TAICHI kernel: [drm:intel_atomic_check.part.134 [i915]]
Encoder config failure
Dec 09 20:44:45 ras-TAICHI kernel: [drm:intel_dump_pipe_config [i915]]
[CRTC:37:pipe A][failed]
Dec 09 20:44:46 ras-TAICHI kernel: [drm:intel_atomic_check.part.134 [i915]]
Encoder config failure
Dec 09 20:44:46 ras-TAICHI kernel: [drm:intel_dump_pipe_config [i915]]
[CRTC:37:pipe A][failed]
Dec 09 20:44:46 ras-TAICHI kernel: [drm:intel_atomic_check.part.134 [i915]]
Encoder config failure
Dec 09 20:44:46 ras-TAICHI kernel: [drm:intel_dump_pipe_config [i915]]
[CRTC:37:pipe A][failed]
Dec 09 20:44:46 ras-TAICHI kernel: [drm:intel_atomic_check.part.134 [i915]]
Encoder config failure
Dec 09 20:44:46 ras-TAICHI kernel: [drm:intel_dump_pipe_config [i915]]
[CRTC:37:pipe A][failed]
Dec 09 20:44:46 ras-TAICHI kernel: [drm:intel_atomic_check.part.134 [i915]]
Encoder config failure
Dec 09 20:44:46 ras-TAICHI kernel: [drm:intel_dump_pipe_config [i915]]
[CRTC:37:pipe A][failed]
Dec 09 20:45:00 ras-TAICHI kernel: [drm:intel_crt_get_edid [i915]] CRT GMBUS
EDID read failed, retry using GPIO bit-banging
The laptop begins booting with the Plymouth background/spinner showing. However
at the stage where GDM should be loaded, the login screen is not displayed:
* If the inner screen is not disabled by kernel parameter it is switched on and
the login screen is displayed there, the outer screen goes blank.
* With kernel params 'video=eDP-1:1920x1080d video=DP-1:1920x1080@60D' the
inner screen stays off but the outer screen is now stuck on the Plymouth
background.
I have updated to the latest nightly intel_drm kernel (4.15.0-994-generic from
<a href="http://kernel.ubuntu.com/~kernel-ppa/mainline/drm-intel-nightly/2017-12-08/">http://kernel.ubuntu.com/~kernel-ppa/mainline/drm-intel-nightly/2017-12-08/</a>).
-------------------------------------------------------------------------------
Background information. The Taichi has never been completely functional under
linux (see <a class="bz_bug_link
bz_status_CLOSED bz_closed"
title="CLOSED WONTFIX - Dual onboard LCD (eDP1 and DP1) cannot turn on DP1 (no backlight), no backlight control but can see screen in reflected light"
href="show_bug.cgi?id=73156">https://bugs.freedesktop.org/show_bug.cgi?id=73156</a>). However it has
been possible on previous Ubuntu versions to enable the the outer screen using
the following workaround:
1. Boot with the lid closed - this causes the BIOS to set the outer screen on
and the underside screen off.
2. Pass the kernel parameter video=DP-1:1920x1080e
3. Wait for X to startup, then either screen can be used.
The outer screen would become disabled if the laptop were suspended (it seems
it can only be powered on by the BIOS). However a workaround for this was to
use pm-hibernate in place of suspend. When the laptop was resumed from
hibernate with the lid closed, the BIOS would re-enable the screen.</pre>
</div>
</p>
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