302 lines
11 KiB
Markdown
302 lines
11 KiB
Markdown
---
|
|
title: Miscellaneous
|
|
x-toc-enable: true
|
|
...
|
|
|
|
TODO: this page is very old, and could do with an update.
|
|
|
|
High Pitched Whining Noise on Idle in Debian or Devuan
|
|
======================================================================
|
|
|
|
Start powertop automatically at boot time.
|
|
|
|
Included with libreboot is a script called 'powertop.debian'. Run this
|
|
as root and it will setup powertop to run with --auto-tune at boot
|
|
time. Load the file in your text editor to see how it does that.
|
|
|
|
sudo ./resources/scripts/misc/powertop.debian
|
|
|
|
Might want to run with --calibrate first
|
|
|
|
If powertop doesn't work, another way (reduces battery life slightly)
|
|
is to add *processor.max\_cstate=2* to the *linux* line in grub.cfg,
|
|
using [this guide](../gnulinux/grub_cbfs.md).
|
|
|
|
High Pitched Whining Noise on Idle in Parabola
|
|
==============================================================
|
|
|
|
The following removes most of the noise. It reduces what is a high
|
|
frequency whine (that not everyone can hear) to a slight buzz (which
|
|
most people can't hear or doesn't bother most people).
|
|
|
|
This is not perfect! The full solution is still not discovered but this
|
|
is a step towards that. Also, in some instances you will need to run
|
|
'sudo powertop --auto-tune' again. This needs to be implemented
|
|
properly in coreboot itself!
|
|
|
|
On the X60 with coreboot or libreboot, there is a high pitched sound
|
|
when idle. So far we have use processor.max\_cstate=2 or idle=halt in
|
|
GRUB. These consume power. Stop using them!
|
|
|
|
Be root
|
|
|
|
su -
|
|
|
|
Installed powertop:
|
|
|
|
pacman -S powertop
|
|
|
|
and added the following to /etc/systemd/system/powertop.service :
|
|
|
|
[Unit]
|
|
Description=Powertop tunings
|
|
|
|
[Service]
|
|
Type=oneshot
|
|
RemainAfterExit=no
|
|
ExecStart=/usr/bin/powertop --auto-tune
|
|
"powertop --auto-tune" still needs a terminal for some reason. Possibly a bug?
|
|
Environment="TERM=xterm"
|
|
|
|
[Install]
|
|
WantedBy=multi-user.target
|
|
|
|
Finally, as root do that:
|
|
|
|
systemctl enable powertop
|
|
systemctl start powertop
|
|
|
|
The next time you boot the system, the buzz will be gone.
|
|
|
|
Might want to run with --calibrate first
|
|
|
|
If powertop doesn't work, another way (reduces battery life slightly)
|
|
is to add *processor.max\_cstate=2* to the *linux* line in grub.cfg,
|
|
using [this guide](../gnulinux/grub_cbfs.md).
|
|
|
|
X60/T60: Serial port - how to use (for dock owners)
|
|
|
|
[Note: using a grsec enabled kernel will disable the powertop function. ](https://en.wikibooks.org/wiki/Grsecurity/Appendix/Grsecurity_and_PaX_Configuration_Options)
|
|
===================================================
|
|
|
|
For the Thinkpad X60 you can use the "UltraBase X6" dock (for the
|
|
X60 Tablet it is called X6 Tablet UltraBase). For the ThinkPad T60, you
|
|
can use the "Advanced Mini Dock".
|
|
|
|
If you are using one of the ROM images with 'serial' in the name, then
|
|
you have serial port enabled in libreboot and you have memtest86+
|
|
included inside the ROM. Connect your null modem cable to the serial
|
|
port on the dock and connect the other end to a 2nd system using your
|
|
USB Serial adapter.
|
|
|
|
On the 2nd system, you can try this (using GNU Screen):
|
|
|
|
sudo screen /dev/ttyUSB0 115200
|
|
|
|
How to quit GNU Screen: Ctrl+A then release and press K, and then press
|
|
Y.
|
|
|
|
There are also others like Minicom but I like GNU Screen
|
|
|
|
By doing this before booting the X60/T60, you will see console output
|
|
from libreboot. You will also see GRUB displaying on the serial output,
|
|
and you will be able to see MemTest86+ on the serial output aswell. You
|
|
can also configure your distro so that a terminal (TTY) is accessible
|
|
from the serial console.
|
|
|
|
The following guide is for Ubuntu, but it should work in Debian and
|
|
Devuan, to enable a serial console using GeTTY:\
|
|
<https://help.ubuntu.com/community/SerialConsoleHowto> (we DO NOT
|
|
recommend Ubuntu, because it contains non-free software in the default
|
|
repos. Use Debian or Devuan)
|
|
|
|
Note: part of the tutorial above requires changing your grub.cfg. Just
|
|
change the `linux` line to add instructions for enabling getty. See
|
|
[../gnulinux/grub\_cbfs.md](../gnulinux/grub_cbfs.md).
|
|
|
|
Finetune backlight control on intel gpu's
|
|
=========================================
|
|
|
|
Sometimes the backlight control value (BLC\_PWM\_CTL) set by libreboot
|
|
is not ideal. The result is either flicker, which could cause nausea or
|
|
epilepsy or an uneven backlight and/or coil whine coming from the
|
|
display. To fix this a different value for the gpu reg BLC\_PWM\_CTL
|
|
needs to be set. See p94 of
|
|
<https://01.org/sites/default/files/documentation/g45_vol_3_register_0_0.pdf>
|
|
for more information on this reg. The tool for setting registry values
|
|
on intel gpu's is included in intel-gpu-tools. Install intel-gpu-tools:
|
|
|
|
sudo apt-get install intel-gpu-tools
|
|
|
|
You can set values:
|
|
|
|
sudo intel_reg write 0x00061254 your_value_in_C_hex_format
|
|
|
|
NOTE: on older versions of this utility, use `intel_reg_write` instead.
|
|
|
|
The value set has the following structure: bits [31:16] is PWM
|
|
divider. PWM / PWM\_divider = frequency bits [15:0] is the duty cycle
|
|
and determines the portion of the backlight modulation frequency. A
|
|
value of 0 will mean that the display is off. A value equal to the
|
|
backlight modulation frequency means full on. The value should not be
|
|
larger than the backlight modulation frequency.
|
|
|
|
On displays with a CCFL backlight start from: 0x60016001 To verify if
|
|
all modes work as desired use: `xbacklight -set 10` and gradually
|
|
increase until 100. Displays with an LED backlight need a lower
|
|
backlight modulation. Do the same thing but start from 0x01290129 . Try
|
|
setting different values until you have found a value which presents no
|
|
issue.
|
|
|
|
It is important to know that there are four failure modes:
|
|
|
|
1. flickering very fast, which could cause epilepsy (frequency is too
|
|
low. decrease divider)
|
|
2. randomly flickering in random intervals - driver IC cannot keep up
|
|
with toggling the mosfet (frequency too fast, increase divider)
|
|
3. frequency is in audible range and causes coils to whine (frequency
|
|
is too high. increase divider)
|
|
4. backlight is uneven. (CCFL specific, frequency is too high. increase
|
|
divider)
|
|
|
|
To check for flickering try moving your laptop while looking at it.
|
|
|
|
A higher frequency equals higher power consumption. You want to find the
|
|
highest good working value.
|
|
|
|
Next this value should be set at boot: either add
|
|
|
|
intel_reg write 0x00061254 <your_ideal_value>
|
|
|
|
NOTE: on older versions of this utility, use `intel_reg_write` instead.
|
|
|
|
before exit 0 in /etc/rc.local or create a systemd service file
|
|
/etc/systemd/system/backlight.service:
|
|
[Unit]
|
|
Description=Set BLC_PWM_CTL to a good value
|
|
[Service]
|
|
Type=oneshot
|
|
RemainAfterExit=no
|
|
ExecStart=/usr/bin/intel_reg write 0x00061254 <your_value>
|
|
[Install]
|
|
WantedBy=multi-user.target
|
|
|
|
|
|
Now start and enable it:
|
|
|
|
sudo systemctl start backlight && sudo systemctl enable backlight
|
|
|
|
Special note on i945:
|
|
|
|
i945 behaves differently. Bit 16 needs to be 1 and the duty cycle is not
|
|
updated when backlight is changed. There are no available datasheets on
|
|
this target so why it behaves in such a way is not known. So to find a
|
|
working value BLC\_PWM\_CTL set bit 16 to 1 and make sure PWM divider ==
|
|
duty cycle. see <https://review.coreboot.org/#/c/10624/> on bit 16. The
|
|
cause of this issue is that i945, in contrast with to GM45, is set to
|
|
work in BLM Legacy Mode. This makes backlight more complicated since the
|
|
duty cycle is derived from 3 instead of 2 registers using the following
|
|
formula: if(BPC[7:0] <> xFF) then BPCR[15:0] \* BPC[7:0]
|
|
Else BPCR[15:0] BPC is LBB - PCI Backlight Control Register, described
|
|
on <http://www.mouser.com/pdfdocs/945gmedatasheet.pdf> on page 315. BPCR
|
|
is BLC\_PWM\_CTL described in
|
|
<https://01.org/sites/default/files/documentation/g45_vol_3_register_0_0.pdf>
|
|
on page 94. More research needs to be done on this target so proceed
|
|
with care.
|
|
|
|
Power Management Beeps on Thinkpads
|
|
===================================
|
|
|
|
When disconnecting or connecting the charger, a beep occurs. When the
|
|
battery goes to a critically low charge level, a beep occurs. Nvramtool
|
|
is included in libreboot, and can be used to enable or disable this
|
|
behaviour.
|
|
|
|
You need to write changes in a libreboot rom image, and flash it, in order
|
|
to apply them. You can either use a pre-compiled rom image, or create an image
|
|
from the current one in your computer. See here
|
|
<https://libreboot.srht.site/docs/gnulinux/grub_cbfs.html#get-the-rom-image> for
|
|
more information on how to do that.
|
|
|
|
Once you have a libreboot rom image, say 'libreboot.rom', you can write
|
|
changes on the image with the following commands.
|
|
|
|
Disable or enable beeps when removing/adding the charger:
|
|
|
|
sudo ./nvramtool -C libreboot.rom -w power_management_beeps=Enable
|
|
sudo ./nvramtool -C libreboot.rom -w power_management_beeps=Disable
|
|
|
|
Disable or enable beeps when battery is low:
|
|
|
|
sudo ./nvramtool -C libreboot.rom -w low_battery_beep=Enable
|
|
sudo ./nvramtool -C libreboot.rom -w low_battery_beep=Disable
|
|
|
|
You can check that the parameters are set in the image with :
|
|
|
|
sudo ./nvramtool -C libreboot.rom -a
|
|
|
|
Finally, you need to flash the rom with this new image. See here
|
|
<https://libreboot.srht.site/docs/gnulinux/grub_cbfs.html#with-re-flashing-the-rom>
|
|
for a detailed explanation.
|
|
|
|
Get EDID: Find out the name (model) of your LCD panel
|
|
=====================================================
|
|
|
|
Get the panel name:
|
|
|
|
sudo get-edid | strings
|
|
|
|
Or look in `/sys/class/drm/card0-LVDS-1/edid`
|
|
|
|
Alternatively you can use i2cdump. In Debian and Devuan, this is in the
|
|
package i2c-tools.
|
|
|
|
sudo modprobe i2c-dev
|
|
sudo i2cdump -y 5 0x50 (you might have to change the value for
|
|
|
|
-y)
|
|
|
|
sudo rmmod i2c-dev
|
|
|
|
You'll see the panel name in the output (from the EDID dump).
|
|
|
|
If neither of these options work (or they are unavailable), physically
|
|
removing the LCD panel is an option. Usually, there will be information
|
|
printed on the back.
|
|
|
|
e1000e driver trouble shooting (Intel NICs)
|
|
===========================================
|
|
|
|
Example error, ¿may happen on weird and complex routing schemes(citation
|
|
needed for cause):
|
|
|
|
e1000e 0000:00:19.0 enp0s25: Detected Hardware Unit Hang
|
|
|
|
Possible workaround, tested by Nazara: Disable C-STATES.
|
|
|
|
*NOTE: this also disables power management, because disabling C-States
|
|
means that your CPU will now be running at full capacity (and therefore
|
|
using more power) non-stop, which will drain battery life if this is a
|
|
laptop. If power usage is a concern, then you should not use this.
|
|
(we're also not sure whether this workaround is appropriate)*
|
|
|
|
To disable c-states, do this in GNU+Linux:
|
|
|
|
for i in /sys/devices/system/cpu/cpu/cpuidle/state/disable;
|
|
do
|
|
echo 1 > $i;
|
|
done
|
|
|
|
You can reproduce this issue more easily by sending lots of traffic
|
|
across subnets on the same interface (NIC).
|
|
|
|
More information, including logs, can be found on [this
|
|
page](http://web.archive.org/web/20210416010634/https://notabug.org/libreboot/libreboot/issues/23).
|
|
|
|
USB keyboard wakeup on GM45 laptops
|
|
===================================
|
|
|
|
Look at resources/scripts/helpers/misc/libreboot\_usb\_bugfix
|
|
|
|
Put this script in /etc/init.d/ on debian-based systems.
|