Why doesn't ofono match all +CGEV notification ? How can I implement a GPRS watchdog ?

[Viallard Anthony <viallard@syscom-instruments.com>]

[-- Attachment #1: Type: text/plain, Size: 2292 bytes --]

Hello,

I'm looking for an issue with GPRS. I have the SIMCOM5216E module with 
ofono 1.12. The problem was see in France with SFR provider. I didn't 
reproduce this with another provider and in another country... But maybe 
it's a question of uptime...

During a good period of time, my device is well connected through the 
GPRS connection. All work perfectly. In recent log, I can see the GPRS 
is reactivated several time along the weeks but the PPP is back online 
soon after.

But, few days ago, I saw the GPRS connection was unusable for 10 days. I 
saw the problem began the 12th February. According to different logs, 
the network connectivity have began to fail since the 2th February. 
Unfortunately, I couldn't get logs from ofono during the period of time 
(it's an embedded device, so the size of the log file is only 64k bytes. 
But it will be a good idea for the future to increment it ...). However, 
the device had others logs. I could see the log from our program that 
deals with ofono (it sends dbus commands and listen for dbus signals) 
and I saw there is a blank period from the 2th to the 12th. It's like 
ofono or the module was dead.

So, I begin to read the code, especially the simcom driver, to see if I 
miss something. And I see something weird.

According to the SIMCOM AT document, the +CGEV notification can be send 
with this list of event:

  REJECT
  NW REACT
  NW DEACT
  ME DEACT
  NW DETACH
  ME DETACH
  NW CLASS
  ME CLASS

But in gprs-context.c, I see we deal only with the "NW DETACH" event. 
Maybe It's the point. Maybe the modem send to ofono an another event and 
therefore ofono begins to be in incorrect state about the GPRS 
connection... Is it possible ?

Otherwise, I'm thinking about implement a GPRS watchdog. Does it exist 
an AT command which could do that ? My idea is to send an AT command 
each XX period of time and check the GPRS connection is really here.

Regards,
Anthony Viallard.

-- 
-----------------------------------------
Viallard Anthony    (+41 024 455 24 82)
[ Embedded System | Software Designer ]
-----------------------------------------
   Syscom Instruments SA
   Rue de l'industrie 21
   1450     Sainte-Croix
-----------------------------------------