Hey all, The extended signal information interface only allowed to configure a fixed polling rate as the method to update the values reported by the interface properties. E.g. the user could say, please update the interface properties every 30s. But polling is far from optimal, it drains battery, and in lots of scenarios the signal quality updates could even be rare.
Modems also allow configuring threshold based signal quality update reporting, so that the modem emits indications every time the signal changes according to what we have configured. Some modems allow to say "please notify every time the signal changes more than 10dBm w.r.t. the last value", some others allow to say "please notify every time the signal crosses a given set of fixed levels, e.g. -60dBm, -70dBm, -80dBm, -90dBm". This new API proposal tries to use the first method, with the users providing one single value (the difference of the value between reports) as threshold; and for MBIM devices this is fine. For QMI I would say we can convert the user provided value into a list of fixed levels, and use those to configure the NAS Signal Strength or NAS Signal Info indications (with the known limitations in the amount of levels we can propose...). The suggested API update also introduces support for reporting channel bit error rate measurements, in percentage, as well as configuring thresholds for that value. See https://gitlab.freedesktop.org/mobile-broadband/ModemManager/-/merge_requests/649 Comments? -- Aleksander https://aleksander.es