Linux 5.13 To Allow Controlling The Second Fan On The Lenovo ThinkPad X1 Carbon Gen 9
Sent in as a fix for the ongoing Linux 5.13 cycle is enabling the ThinkPad ACPI driver to control the second fan on this latest ThinkPad X1 Carbon laptop. This support is necessary so the secondary fan doesn't simply run at a constant rate.
The ThinkPad ACPI driver has had secondary fan support for quite a while now and enabled for the relevant Lenovo laptops having the extra fan, but requires per-device whitelisting via a quirk table based on ACPI information. It's that addition for the ThinkPad X1 Carbon Gen 9 that has worked its way into Linux 5.13.
That addition was sent in along with other platform-drivers-x86 fixes today and subsequently merged.
The ThinkPad X1 Carbon "G9" is a nice Tiger Lake laptop from the hardware perspective while the Linux support now seems to be in good standing. While Lenovo has been contributing more and more to Linux with a focus on offering more OEM preloads, this second fan support talked about today comes thanks to an independent user.