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diff --git a/docs/misc/index.md b/docs/misc/index.md new file mode 100644 index 00000000..6db759a7 --- /dev/null +++ b/docs/misc/index.md @@ -0,0 +1,358 @@ +<div class="section"> + +Miscellaneous {#pagetop} +============= + +Or [Back to main index](../). + +- [High Pitched Whining Noise on Idle (how to remove in Debian or + Devuan)](#debian_powertop) +- [High Pitched Whining Noise on Idle (how to remove in + Parabola)](#high_pitch_parabola) +- [X60/T60: Serial port - how to use (for dock owners)](#serial) +- [Power Management Beeps on Thinkpads](#powerbeeps) +- [Using diff and patch](patch.html) +- [Finetune backlight control on intel gpu's](#backlight%20control) +- [Get EDID: Find out the name (model) of your LCD + panel](#get_edid_panelname) +- [How to enable EHCI debugging on the BeagleBone + Black](bbb_ehci.html) +- [e1000e driver trouble shooting (Intel NICs)](#e1000-hang) + +</div> + +<div class="section"> + +High Pitched Whining Noise on Idle (how to remove in Debian or Devuan) {#debian_powertop} +====================================================================== + +<div class="subsection"> + +Start powertop automatically at boot time {#debian_powertop_autostart} +----------------------------------------- + +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.html). + +</div> + +[Back to top of page](#pagetop) + +</div> + +<div class="section"> + +High Pitched Whining Noise on Idle (how to remove in Parabola) {#high_pitch_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.html). + +[Back to top of page](#pagetop) + +</div> + +<div class="section"> + +X60/T60: Serial port - how to use (for dock owners) {#serial} +=================================================== + +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.html](../gnulinux/grub_cbfs.html). + +[Back to top of page](#pagetop) + +</div> + +<div id="backlight control" class="section"> + +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>** + +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> + +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. + +</div> + +<div id="powerbeeps" class="section"> + +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. + +Disable or enable beeps when removing/adding the charger:\ +\$ **sudo ./nvramtool -w power\_management\_beeps=Enable**\ +\$ **sudo ./nvramtool -w power\_management\_beeps=Disable** + +Disable or enable beeps when battery is low:\ +\$ **sudo ./nvramtool -w low\_battery\_beep=Enable**\ +\$ **sudo ./nvramtool -w low\_battery\_beep=Disable** + +A reboot is required, for these changes to take effect. + +</div> + +<div class="section"> + +Get EDID: Find out the name (model) of your LCD panel {#get_edid_panelname} +===================================================== + +Get the panel name with **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. + +[Back to top of page.](#pagetop) + +</div> + +<div class="section"> + +e1000e driver trouble shooting (Intel NICs) {#e1000-hang} +=========================================== + +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](https://notabug.org/vimuser/libreboot/issues/23). + +</div> + +<div class="section"> + +USB keyboard wakeup on GM45 laptops {#usb_keyboard_gm45} +=================================== + +Look at resources/scripts/helpers/misc/libreboot\_usb\_bugfix + +Put this script in /etc/init.d/ on debian-based systems. + +</div> + +<div class="section"> + +Copyright © 2014, 2015, 2016 Leah Rowe <info@minifree.org>\ +Permission is granted to copy, distribute and/or modify this document +under the terms of the Creative Commons Attribution-ShareAlike 4.0 +International license or any later version published by Creative +Commons; A copy of the license can be found at +[../cc-by-sa-4.0.txt](../cc-by-sa-4.0.txt) + +Updated versions of the license (when available) can be found at +<https://creativecommons.org/licenses/by-sa/4.0/legalcode> + +UNLESS OTHERWISE SEPARATELY UNDERTAKEN BY THE LICENSOR, TO THE EXTENT +POSSIBLE, THE LICENSOR OFFERS THE LICENSED MATERIAL AS-IS AND +AS-AVAILABLE, AND MAKES NO REPRESENTATIONS OR WARRANTIES OF ANY KIND +CONCERNING THE LICENSED MATERIAL, WHETHER EXPRESS, IMPLIED, STATUTORY, +OR OTHER. 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