📣 Call for Reports

[h4fnp]

The compatibility table in the README lists ThinkPads the kernel flags as "non-standard EC" (NS). Only the L13 Yoga Gen 2 is confirmed (✅) so far — every other model is ❓ ("no report yet").

If you have one of those models, or any ThinkPad whose fan runs constantly with no way to slow it down in Linux, please add a report here.

The report tool is read-only — it never writes EC registers, doesn't need ec_sys.write_support, and works with Secure Boot enabled. See the report instructions in the README for how to run it. It takes about three minutes (idle → load → idle) and writes a .txt file.

Post that file here (paste it in a code block or attach it), and include your model and BIOS version (dmidecode -s bios-version, e.g. R1FET64W (1.38)). Existing reports are collected in the reports/ folder — you can also submit there by pull request if you prefer.

A "doesn't work" result is just as useful as a working one. Thanks for helping!

[zesaver]

Hello,

• Model: X13 Yoga (Gen 1)
• Bios: N2UET74W (1.54 )
• Report file: tpnsfand-report-unknown-20260622-161255.txt
• Comments: the fan on my laptop sometimes works without pauses, sometimes is silent even during stress load. I have found no way to control it yet.

Thank you,

[h4fnp]

Thanks a lot for taking the time to run the report @zesaver!

I've added it to the repo.

Good news: your X13 Yoga Gen 1 uses the same EC fan registers as my L13 Yoga Gen 2 — 0x93 for the control mode and 0x94 for speed (inverse, RPM ≈ 491520 / value). The 1927 RPM you see at the start is just the "fan off" reading (491520 / 255). So tpnsfand would very likely be able to drive your fan once ec_sys.write_support=1 is set.

The catch: I don't think it'll help you much. In your log the fan ramps all the way up to ~4400 RPM and stays there, yet the CPU never drops below ~77 °C — even at the very end, when the workload is already idle again. When a fan at full speed can't cool an idle CPU, the airflow itself is probably restricted. The most likely cause is a dust-clogged fan.

So before anything else I'd check and clean the fan:

• Cleaning walkthrough (L13, same chassis family — the procedure is essentially identical): https://www.ifixit.com/Guide/Thinkpad+L13+Cleaning+Fan+&+Replacing+Thermal+Paste/152099
• Removing the base cover on your exact model: https://download.lenovo.com/pccbbs/pubs/x13yoga_gen1/html_en/index.html#t=en%2FBase_cover_assembly_(topic)_T0000737452.html%23ReplacingTheBaseCoverAssembly-82D54F38

BTW — unrelated to the above — your BIOS is a few releases behind (1.54; the latest is 1.60): https://pcsupport.lenovo.com/us/en/products/laptops-and-netbooks/thinkpad-x-series-laptops/thinkpad-x13-yoga-gen-1/downloads/ds544145.