ps-min-modem / ps-max-modem not working on esp32c3

[rbomze]

Hi, today i extensively experimented with esp-rs in combination with esp-wifi and embassy-rs on the esp32 platform. On a esp32c3 everything works fine as long there is no modem sleep enabled. Enabling eg. ps-min-modem via a feature for esp-wifi, allows to connect to an AP without any problems, but any further connection attempts via socket fail. Not a single packet is received on the other side (i am getting 'ConnectionResets' as a fault).

Curious, because i was always using modem sleep in all esp-idf projects before (on the 'classic' esp32, where it is the default btw.) i tried to run (almost) the identical code on a 'classic' esp32. This time 'ps-min-modem' (and 'ps-max-modem') worked without any problems. The only real difference between both codes are the timers:

    #[cfg(target_arch = "riscv32")]
    let timer = esp_hal::systimer::SystemTimer::new(peripherals.SYSTIMER).alarm0;
    #[cfg(target_arch = "xtensa")]
    let timer = esp_hal::timer::TimerGroup::new(peripherals.TIMG1, &clocks).timer0;

Could it be that the alarm0 timer is kind of too inaccurate to handle the right timing of the beacons and DTIMs? Btw. i tried different intervals for the the beacons [between 100-500] and DTIMs [between 2-5] - on the esp32c3 nothing worked with modem sleep enabled, on the esp32, as expected, i got more latency with higher intervals, but it always worked.