With the Cap powered, I2C bus 1 doesn't only fail reads: some come
back garbled (a capacity of 56414, clamped to a confident 100), and
the kernel's bq27xxx driver caches whatever it read, failure or
garbage, for five seconds. Retrying 0.1 s apart only re-read the
cache, so every retry missed.
Now an unreadable or out-of-range percent is asked again 5.5 s later,
past the cache; a step of more than 5 points between polls waits for
the next poll to confirm it, which catches garbage that lands inside
0-100; and the sysfs reads leave the event loop, since a failing
transfer on that bus takes its time. Measured on the device with the
Cap on: a steady 96%, where it showed nothing or 100 before.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Jean-Pierre MartineauandClaude Opus 5.5
db4cc657fe