09-25-2020, 05:24 AM
Quote:If proper power down is to be implemented in the kernel for the modem, to allow safe shutdown of the modem before turning off the 4g-pwr-bat, kernel has to be able to signal to the modem to shut down and wait 30s.
This is not possible on braveheart.
Without this signal, kernel can't do anything to shut down the modem, and would have to rely on userspace to properly manage the modem power up/down sequence. Relying on userspace risks users shutting down the modem without proper wait time of 30s, risking modem damage (flash data corruption).
I believe on PMOS they still wait 30 seconds for shutdown even on 1.2a.
It's not necessary on the latest Quectel firmware, it safely shuts down in 2s. The question is only if it's getting the shutdown message.
