Bug #445


Thinkpad X200 wifi issue

Added by Masc Masc about 1 year ago. Updated 10 months ago.

board support
Target version:
Start date:
Due date:
% Done:


Estimated time:
Affected versions:
Needs backport to:
Affected hardware:
Affected OS:


Compiled coreboot latest revision from source and built a coreboot rom image for X200 with SeaBIOS (also tried with Grub as a payload). The laptop beeps and the power LED flashes at startup and the wifi card does not work (cannot enable wifi in OS).
The operating system is Debian Bullseye and the wifi card is an Atheros AR5B95. The OS boots normally, but no wifi is available. The wifi card has been tested and works fine with latest stable libreboot release.


config (18.1 KB) config Masc Masc, 01/07/2023 09:10 PM
cbmem.txt (42.4 KB) cbmem.txt Masc Masc, 01/07/2023 09:10 PM
dmesg.txt (62.8 KB) dmesg.txt Masc Masc, 01/07/2023 09:13 PM
lspci_nn_libreboot.txt (2.42 KB) lspci_nn_libreboot.txt Masc Masc, 01/08/2023 05:46 PM
lspci_tv_libreboot.txt (1.47 KB) lspci_tv_libreboot.txt Masc Masc, 01/08/2023 05:46 PM
lspci_vvvxx_libreboot.txt (31.1 KB) lspci_vvvxx_libreboot.txt Masc Masc, 01/08/2023 05:47 PM
lspci_nn_coreboot.txt (2.42 KB) lspci_nn_coreboot.txt Masc Masc, 01/08/2023 05:47 PM
lspci_tv_coreboot.txt (1.48 KB) lspci_tv_coreboot.txt Masc Masc, 01/08/2023 05:47 PM
lspci_vvvxx_coreboot.txt (31.6 KB) lspci_vvvxx_coreboot.txt Masc Masc, 01/08/2023 05:49 PM
Actions #1

Updated by Paul Menzel about 1 year ago

Please attach the .config and the coreboot logs (cbmem -1) and Linux logs (dmesg).

Updated by Masc Masc about 1 year ago

Actions #3

Updated by Paul Menzel about 1 year ago

Thank you for providing these files. As it’s a PCIe card, please also attach the output of lspci -nn, lspci -tv and sudo lspci -vvvxx – preferably with (working) Libreboot and (problematic) coreboot.

Updated by Masc Masc about 1 year ago

An interesting development happened. I flashed libreboot and collected the requested output from lspci (attached) with the working configuration. After that, I reflashed the identical problematic coreboot.rom and surprisingly the wifi card started working. I rebooted several times trying to reproduce the wifi problem, but was unable to do so. The wifi seems to work properly. I attached the lspci outputs for coreboot as well. However, the beep and power LED flashing persists only with coreboot, even though now the wifi works. Could this possibly be a hardware issue?

Actions #5

Updated by Martin Roth about 1 year ago

It's entirely possible that coreboot is violating some of the power-on timings of that wifi module. This could cause it to work some of the time, but fail at other times.

To fix this, or determine if this actually is a problem, someone would have to grab the datasheet for the the chip on that module and see what the timings are supposed to be. There are probably GPIOs to control the various power and enable signals to the chip. We'd have to see when those are actually being set to tell if the spec is being violated.

This is entirely a guess on my part based on the work I've done on chromebooks getting the power-on timings for the PCIe slots to meet the specs for all of the modules we were using on a build.

It's also possible as you mentioned that there's just something wrong with your individual module that's causing it to be flaky.

Actions #6

Updated by Masc Masc about 1 year ago

I would like to add a latest update. I have been having the wifi card problem intermittently and I decided to change it.
I purchased another Atheros AR5B95 and so far the problem seems resolved (I have been testing it for a few days and the issue seems gone), supporting the idea in Martin Roth's post.

Actions #7

Updated by Martin Roth 10 months ago

  • Category set to board support
  • Status changed from New to Closed

Marking as resolved, but we should look at a better method of making sure the GPIOs for an individual platform have the flexibility to adjust the timing to meet any card's power-on spec.


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