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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 - "vbetool dpms on" doesn't work with i915 Haswell"
href="https://bugs.freedesktop.org/show_bug.cgi?id=92866">92866</a>
</td>
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<tr>
<th>Summary</th>
<td>"vbetool dpms on" doesn't work with i915 Haswell
</td>
</tr>
<tr>
<th>Product</th>
<td>DRI
</td>
</tr>
<tr>
<th>Version</th>
<td>unspecified
</td>
</tr>
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<th>Hardware</th>
<td>x86 (IA32)
</td>
</tr>
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<th>OS</th>
<td>Linux (All)
</td>
</tr>
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<th>Status</th>
<td>NEW
</td>
</tr>
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<th>Severity</th>
<td>normal
</td>
</tr>
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<th>Priority</th>
<td>medium
</td>
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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>holgerschurig@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>This bug is about the kernel module i915 in text (framebuffer) mode. It's not
about any X11 driver. So I hope the Component is right.
I tested it with Linux 3.18.24 and 4.3.
What I want to achive: I want to turn off the backlight. On some other i915
based hardware (8086:a011) this worked with "vbetool dpms on" and back on with
"vbetool dpms off".
With my i915/Haswell (8086:0a16) the "turn off" part works, albeit I get error
messages in dmesg. But the "turn on" doesn't work: Backlight goes on, but LCD
display stays black.
root:/sys# dmesg -c >/dev/null
root:/sys# vbetool dpms off
root:/sys# dmesg -c
[ 325.704229] [drm:intel_uncore_check_errors [i915]] *ERROR* Unclaimed
register before interrupt
[ 326.290205] [drm:intel_uncore_check_errors [i915]] *ERROR* Unclaimed
register before interrupt
root:/sys# vbetool dpms on
root:/sys# dmesg -c
[ 340.408883] [drm:intel_uncore_check_errors [i915]] *ERROR* Unclaimed
register before interrupt
[ 340.682288] [drm:intel_set_cpu_fifo_underrun_reporting [i915]] *ERROR*
uncleared fifo underrun on pipe A
[ 340.682348] [drm:intel_cpu_fifo_underrun_irq_handler [i915]] *ERROR* CPU
pipe A FIFO underrun
When I run "vbetool vbestate save" I also get a number of error messages, as
well as with "vbetool vbestate restore". It however restores the display
partially: But it's greatly enlarged, probably the upper
left quarter of the former display now magnified over the whole screen.
Some dmesg output related to the i915/Haswell:
[ 0.221025] vgaarb: setting as boot device: PCI:0000:00:02.0
[ 0.221099] vgaarb: device added:
PCI:0000:00:02.0,decodes=io+mem,owns=io+mem,locks=none
[ 0.221168] vgaarb: loaded
[ 0.221225] vgaarb: bridge control possible 0000:00:02.0
...
[ 2.969865] [drm] Memory usable by graphics device = 2048M
[ 2.969930] [drm] Replacing VGA console driver
[ 2.970595] Console: switching to colour dummy device 80x25
[ 2.976807] [drm] Supports vblank timestamp caching Rev 2 (21.10.2013).
[ 2.976814] [drm] Driver supports precise vblank timestamp query.
[ 2.976895] vgaarb: device changed decodes:
PCI:0000:00:02.0,olddecodes=io+mem,decodes=io+mem:owns=io+mem
[ 3.003257] fbcon: inteldrmfb (fb0) is primary device
[ 3.005096] ACPI: Video Device [GFX0] (multi-head: yes rom: no post:
no)
[ 3.005312] input: Video Bus as
/devices/LNXSYSTM:00/LNXSYBUS:00/PNP0A08:00/LNXVIDEO:00/input/input17
[ 3.005362] [drm] Initialized i915 1.6.0 20150731 for 0000:00:02.0 on
minor 0
[ 4.092573] Console: switching to colour frame buffer device 128x48
[ 4.096012] i915 0000:00:02.0: fb0: inteldrmfb frame buffer device
...
vbetool is 1.1
If there is something else beside vbetool I would use it. The files in
/sys/class/backlight/intel_backlight/* seem to be no-op on my board.
One thing: after running "vbotool dpms off", the file dpms in
/sys/class/drm/card0-DP-2/ stays in state "On". But it's the only connected
port:
root@hwtester:~# grep -d skip . /sys/class/drm/*/enabled
/sys/class/drm/card0-DP-1/enabled:disabled
/sys/class/drm/card0-DP-2/enabled:enabled
/sys/class/drm/card0-HDMI-A-1/enabled:disabled
/sys/class/drm/card0-HDMI-A-2/enabled:disabled
root@hwtester:~# grep -d skip . /sys/class/drm/*/dpms
/sys/class/drm/card0-DP-1/dpms:Off
/sys/class/drm/card0-DP-2/dpms:On
/sys/class/drm/card0-HDMI-A-1/dpms:Off
/sys/class/drm/card0-HDMI-A-2/dpms:Off</pre>
</div>
</p>
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