Please add P53

[kresbeatz]

Please, add P53 in your patch :) If I understand correctly (according to this https://forums.mydigitallife.net/threads/oa-2-x-slic-oemcert-collection.5952/page-84#post-1559468), it's code is also N2N. I can do all the testings needed. Thanks in advance!

[civic9]

It should work with P53 without any changes. just try.
However, I consider this project as deprecated - support for 2nd fan is included since 5.8.1 kernel, so no patch is needed (however there is simpler version included, both fans are always running at the same speed, but it is enough for most purposes).

[kresbeatz]

Thank you for the fast reply. I'm on P53 on Arch and sensors command shows only fan1 under thinkpad-isa-0000. I'm on the latest kernel (5.9.6-arch1-1) and installed lm-sensors and thinkfan via pacman. Will investigate it further.

[kresbeatz]

I think I understand now. It's strange, but when I'm on AC I'm almost constantly hearing the fan, but when I'm on battery it start spinning only after 50C as it should. Probably it is related to my thinkfan.conf rather than kernel. However I still see only one fan with "sensors" command. Is it expected behaviour?

[civic9]

Oops... I just checked now... unfortunately only codes for P50,P70,P51,P71,P52,P72 and X1 extreme (1,2nd gen) are in the 5.8/5.9 kernels. Patch for X1E 3rd gen is in the queue too. No N2N code for P73/P53. For now you can patch current kernel on your own with patch something like that:
https://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86.git/commit/?h=review-hans&id=c758be8e1d06f3989d2cfd0efd182b67773a88f9
Add another line with your code, e.g.

TPACPI_Q_LNV3('N', '2', 'N', TPACPI_FAN_2CTL),

after last entry in tpacpi_quirk fan_quirk_table.

sensors should show two fans:

thinkpad-isa-0000
Adapter: ISA adapter
fan1:        2469 RPM
fan2:        2166 RPM
temp1:        +54.0°C  
...

[kresbeatz]

Thank you very much, working like a charm! I hope it will be added to the next kernel release :)