Re: acpi_cmbat with charge-limited battery
Date: Mon, 06 Mar 2023 03:33:14 UTC
On Sun, Mar 5, 2023 at 7:20 PM Kyle Evans <kevans@freebsd.org> wrote: > Hello! > > I've dealt with this mainly over the weekend, but my solution was to > just disable acpi_cmbat entirely, which is maybe not the best solution > but I can't tell if this should be considered a firmware bug or if > it's something we could find a way to workaround in the kernel. > > Basically, I've set the firmware on my frame.work laptop to limit the > battery charge to 80%. When it hits 80% while plugged in, things get a > little funky- I assume it's because the firmware's trying to carefully > maintain the limit, but I end up getting (at least) one acpi > notification per second, alternating between BST_CHANGE/BIX_CHANGE, > which in turn drives up CPU usage as we tap it out to devd and upowerd > picks it up. upowerd ends up pegging a core consistently. > > Should we be rate-limiting these devd notifications? Is this even > reasonable behavior for the firmware? I'm not really sure how other OS > behave here, but I haven't really seen any complaints from other > framework'ers. > Seems like this is crappy firmware behavior and we should rate limit in the driver... It's not useful information to be sharing once a second... Warner