Kernel 6.12.20+rpt-rpi appears to have broken SenseHat support

Start by reproducing the failure on a Raspberry Pi 5 with kernel 6.12.20+rpt-rpi, the SenseHat connected, and dtparam=i2c_arm=on; compare it with 6.6.74+rpt-rpi. Use the traceback in /usr/lib/python3/dist-packages/sense_hat/sense_hat.py, especially _init_humidity, as the entry point. Done means SenseHat humidity initialization works after upgrading to 6.12.20.

Describe the bug

After upgrading from kernel 6.6.74+rpt-rpi to 6.12.20+rpt-rpi the device init fails:

Traceback (most recent call last):
File "/usr/lib/python3/dist-packages/sense_hat/sense_hat.py", line 640, in temp
     return self.get_temperature_from_humidity()
            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/lib/python3/dist-packages/sense_hat/sense_hat.py", line 612, in get_temperature_from_humidity
     self._init_humidity()  # Ensure humidity sensor is initialised
     ^^^^^^^^^^^^^^^^^^^^^
   File "/usr/lib/python3/dist-packages/sense_hat/sense_hat.py", line 579, in _init_humidity
     raise OSError('Humidity Init Failed')
 OSError: Humidity Init Failed

Downgrading the kernel with:

sudo apt purge linux-image-6.12.20+rpt-rpi-2712 linux-image-6.12.20+rpt-rpi-v8
sudo apt reinstall linux-image-6.6.74+rpt-rpi-2712 linux-image-6.6.74+rpt-rpi-v8

makes it work again without any other changes.

Steps to reproduce the behaviour

Upgrade the kernel to 6.12.20 (sudo apt update; sudo apt dist-upgrade).

Having the SenseHat connected and dtparam=i2c_arm=on in /boot/firmware/config.txt, try to run, e.g.

from sense_hat import SenseHat

sense = SenseHat()
sense.clear()

temp = sense.get_temperature_from_humidity()
print(temp)

Notice that an OSError: Humidity Init Failed is thrown.

Device (s)

Raspberry Pi 5

System

Raspberry Pi reference 2023-10-10
Generated using pi-gen, https://github.com/RPi-Distro/pi-gen, 962bf483c8f326405794827cce8c0313fd5880a8, stage2

2025/03/19 13:41:26 
Copyright (c) 2012 Broadcom
version cec1d3ae (release) (embedded)

Linux 6.12.20+rpt-rpi-2712 #1 SMP PREEMPT Debian 1:6.12.20-1+rpt1 (2025-03-19) aarch64 GNU/Linux

Logs

No response

Additional context

No response