Howto - automatically recover your modem and mobile data after deep sleep

[scholbert]

Basically, it's just a userspace re-implementation of megi's power management driver, with an mguard-like feature for modem recovery (force disconnect/reconnect the modem if it doesn't come back online after suspend).

This also means it can be used with any kernel, except megi's as it conflicts with its own modem management driver.

Hi a-wai,

many progress had been made in the last weeks. Great work!!!
Though i kept upgrading from 1113 image, i guess i will do a clean flash to my device again with the latest 1215 image.
BTW, i'm running Mobian on V1.2b mainboard hardware.

Let me describe what i observed concerning modem behaviour.
I kept my device in flight mode. After power up i am directly prompted to enter SIM pin.
Everything fine, modem usb ports are all there. Modem settings are reachable through UI. Then let the device go directly into sleep -> enter crust mode.

After a while power up, by the phone by pressing the power button. Modem had completely gone.
Checking dmesg gives there'd been no usb enumeration/no ports at all.

Then again some deep sleep, tried again... throwing some dice and the modem was there again. So it seems not to be a static behaviour.
Anyway most of the time it's gone.

I guess i'll have to dig a little deeper into the code to understand the wake up procedure, when the phone tries to come back to live...
BTW is the DTR-Pin triggered to try and wake up the modem as well?

There'd been some rumours, it's all caused by modems firmware... maybe i'll have to collect some informations on this.

What do you think about the possibility that the usb enumeration got stuck/is not retriggered on the modems side?
The A64 hub would have trouble to get the ports back then.
What if we would be able to switch VBUS of the modem seperately?
I know that this is not possible with the actual hardware, but just in case...

Anyway, hopefully this issue could be solved by software, because i think power management and modem handling is very essential for a mobile.

Best regards,
scholbert