Hi,

<snip>

 > ofonod[1566]: < AT+CPIN?
> ofonod[1566]: drivers/atmodem/sim.c:at_cpin_cb() crsm_pin_cb: READY
> ofonod[1566]: drivers/atmodem/sim.c:at_pin_retries_query()
> ofonod[1566]: <  AT+CPINR
> ofonod[1566]: < AT+CRSM=192,28590,0,0,255
> ofonod[1566]:Querying remaining pin retries failed
> ofonod[1566]: < AT+CRSM=192,28589,0,0,255
>
> Once this happens(ofono stop after AT+CRSM), I can only list the modem
> with the feature "sim"

It is hard to tell from your log what is going on.  Is your oFono 
modified in some way?  The AT command logging should print commands 
sent, echo (if any) and command responses.  I'm not seeing that here.

Do you get a response to the last CRSM command sent?  If not, then 
likely the modem crashed.  The two CRSM commands you see above are 
querying EFad and EFphase.  Right after there should be some more EFs 
being read followed by reading of the IMSI (+CIMI)

<snip>

>
> Here is my question,
> 1, why does it happen randomly?

Who knows.

> 2, what does "Querying remaining pin retries failed" mean? this message
> is showing up even when the ofono is working fine.

It just means that the sim atom driver does not implement this 
functionality.  It should probably be changed from a warning to a debug 
message.

> 3, sometimes all the module had been loaded, but the connection manager
> will disappear.

Impossible to tell without a log.

Regards,
-Denis