Raspberry Pi On Linux 4.19 Will Be Able To Report Under-Voltage Issues

The Linux 4.19 kernel will be introducing a new "raspberrypi-hwmon" driver capable of reporting under-voltage conditions for Raspberry Pi boards.

This Raspberry Pi Hwmon driver makes it easy to find out if your ARM SBC is suffering from any under-voltage condition: the driver reports the under-voltage sensor state via a mailbox interface with the VC4 firmware. Undervoltage conditions are then written to the kernel log.

This driver should work going back to the Raspberry Pi A+ and work through the Raspberry Pi 3 B+. Previously Raspbian had its own downstream code while now this Hwmon driver is the first upstream kernel solution.

Just under two hundred lines of code was needed for this new support, which is now staged in arm-soc's for-next branch. This is great to see considering the wide range of environments where Raspberry Pi hardware is deployed with a range of USB power adapters, some of which are not often too reliable.

The Linux 4.19 kernel cycle should kick off in August while the Linux 4.19.0 stable release should be out around October.