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[PLS8-X linux 3.10.y ] network not responding after resume from mem suspend | Telit Cinterion IoT Developer Community

January 17, 2019 - 9:19pm, 2305 views

Hello 

I'v have a fleet of PLS8-X that are deploy on ARM board running 3.10.26. We are using pppd to initiate the connection with the modem. The modem are using the firmware 3.017 . 

First a bit of context:

We can initiate a connection with modem and keep it running until we start doing sleep (echo mem > /sys/power/state  ).  Usually after 10-20 sleep/wake-up (no exact pattern found yet) the network connection will stop responding (PING will timeout ) even if the PPP0 network interface still show up and pppd show no sign of error or disconnection. The usb port ACM0 and ACM1 are still present. 

The cdc_acm driver for the modem clearly show we are entering suspend/resume mode. 

For now the only way to get a connection back is to poweroff the modem using the IGT/EMERGENCY_OFF pin which re-trigger whole process of adding the usb device and driver. 

Issuing the AT command CERR show nothing special. 

my experience with modem is limited 

so I'v got a few question:  

- Is the PLS8-X is known to support linux sleep mode and recover/resume with a network connection still active when using the ACM modem mode and no interruption?  

- Would the WWAN mode support suspend/resume and keep the network connection without any interruption? 

- Would there be an efficient way debug the modem state. 

feel free to ask for any configuration I might have.

Any help would be greatly appreciated. 

Alexandre Leblanc

Alexandre Leblanc