[pi-kernel] Please set CONFIG_RTC_DRV_DS1307=y

[Michael Vogt]

We recently got a bugreport from a user who uses a PI with an external RTC. The chips is a ds3231. The driver for this is currently compiled as a module. Doing RTC as a module is unfortunately broken in the general case today (see https://github.com/systemd/systemd/issues/17737 and https://forum.snapcraft.io/t/adding-ubuntu-core-fails-on-first-boot-with-rtc-is-present/30391/15 for details).

Until a more general fix is available I would like to ask to just compile CONFIG_RTC_DRV_DS1307=y into the kernel that should cover a lot of popular chips and we already build CONFIG_RTC_DRV_DS1307_CENTURY=y

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This bug is missing log files that will aid in diagnosing the problem. While running an Ubuntu kernel (not a mainline or third-party kernel) please enter the following command in a terminal window:

apport-collect 1981078

and then change the status of the bug to 'Confirmed'.

If, due to the nature of the issue you have encountered, you are unable to run this command, please add a comment stating that fact and change the bug status to 'Confirmed'.

This change has been made by an automated script, maintained by the Ubuntu Kernel Team.

[Juerg Haefliger (juergh)]

CONFIG_RTC_DRV_DS1307_CENTURY does not enable a driver but enables a config option for the ds1307 driver.

I really don't want to randomly build modules into the kernel simply because userspace is broken. The raspi kernel is already bloated and reducing usable memory any further is not cool, especially for 512MB Pis.

It seems all we need to do is add the module to the initrd and load it early in the initrd stage, no?