Using Raspberry POE+ hat with bullseye

Ryutaroh Matsumoto

2021-11-28 23:40:02 UTC

I am using Debian Bullseye on a Raspberry PI 4 with a POE+ hat. So far I am
unable to get the fan on the POE+ hat working.

(deleted)

#uname -a
Linux host 5.10.0-9-arm64 #1 SMP Debian 5.10.70-1 (2021-09-30) aarch64 GNU/
Linux

(deleted)

#uname -a
Linux host 5.14.0-0.bpo.2-arm64 #1 SMP Debian 5.14.9-2~bpo11+1 (2021-10-10)
aarch64 GNU/Linux

* Debian arm64 (incl. images from raspi.debian.net) uses the plain upstream linux kernel.
* The plain kernel 5.10 does not have the RPi POE driver.
* 5.14 and later have the RPi POE driver, but the debian kernels do not enable it (so far).

Solutions can be
(1) Compile the kernel by yourself, following https://www.debian.org/doc/manuals/debian-kernel-handbook/ch-common-tasks.html
It takes several hours but possible on RPi4.

(2) or file a bug report to the Debian linux source package requesting enablement of
CONFIG_PWM_RASPBERRYPI_POE.
As far as I can remember, a request of a new device driver into the kernel package
should verify working of that device driver with its corresponding device.
Unfortunately, I don't have POE so I cannot help with verification.

Best regards, Ryutaroh