Some issues with coreboot on T420 (touchpad and phone jack)
Synaptics Touchpad and Trackpint driver doesnot work originally under Windows 10 (but work under linux). The reason is the ACPI\VEN_PNP&DEV_0F13 generated by the coreboot can not be recognized by the driver. To workaround this, uncomment this line (MS_GROUP01_InterTouch_Inst,*PNP0F13) in the SynPD.inf file of Synaptics offcial driver. The PNP0F13 is probably adopted from previous models but no longer the name for T420. Is it possible to replace it with a right one?
The phone jack does not produce sound in Windows 10. It works fine under linux.
Throttling not work natively. On linux we have to install thermald to prevent overheating. But there seems not an equivalent software under Windows.
#1 Updated by Mark Smith about 1 month ago
With the current build as of April 27th 2020, the touchpad seems to get recognized properly under Windows 10. Windows update fetched the correct driver, and trackpoint scrolling also works properly like it has done on Linux all this time.
Throttling is also working nicely under Arch, Ubuntu and Windows 10. I've played games and the CPU has kept it's temperature under control.
The audio problem on the other hand still remains. No matter the drivers, the moment I plug any pair of headphones in, the speakers will get muted like usual, but absolutely no sound will play from the jack. This only happens under Windows 10. Under Linux both my headphones and microphone are detected.
I'm not sure what I can do to help, but since this is the very final issue preventing me from using coreboot and Windows 10 I'm willing to try anything. I would have used Linux only, but there is some software I am required to use for school and work which only works properly under Windows.
#2 Updated by Paul Menzel about 1 month ago
Pok, if you can still test this, it’d be great, if you verified Mark’s findings.
For the Windows audio issue, what driver version is used? Can you please attach the output of
alsa-info.sh , in Debian it’s packaged in alsa-utils as
/usr/sbin/alsa-info, when running under the vendor firmware and when running coreboot?
I would have used Linux only, but there is some software I am required to use for school and work which only works properly under Windows.
Using a virtual machine or Wine/CrossOver might be an option here.
#3 Updated by Mark Smith about 1 month ago
- File audio drivers generic windows.png added
- File audio drivers conexant.png added
- File alsa-info.txt added
These are the 2 drivers that I've been using on Windows 10. First are the generic drivers that Windows automatically fetched, second are with the official Conexant Audio Software version 188.8.131.52 from Lenovo's website.
The problem is the same with either driver.
I have included the alsa-info log as well. I ran it on Ubuntu 20.04 with the latest build of coreboot.
Unfortunately I'm unable to test in when running under the vendor firmware as the T420 requires complete disassembly to flash coreboot when the vendor firmware is installed. It's possible to solder wires to the debug pins and be able flash the BIOS chip directly without complete disassembly again, but I haven't been able to do that.
I will ask other people with the T420 if they're able to run alsa-info with the stock BIOS though.