Sierra C885 nightmares

[Aleksander Morgado <aleksander lanedo com>]

Hey Dan, Marius & everybody,

I recently got a <irony>wonderful</irony> Sierra Wireless C885 modem
from eBay...

I fixed several obvious issues in MM git master to have it connected,
but I'm stuck with several things that I don't really know how to
properly handle.

1) SIM lock after power up
So, we power-down the modem with CFUN=4 and we recover full
functionality mode with CFUN=1,0 (0 to avoid the reset). But, if the SIM
has PIN enabled, the modem will require SIM unlock before going on. If
you don't provide the SIM, it will end up replying ERROR to every next
command sent. Dan: I believe you already saw this in some other modems,
was it because of the missing SIM PIN?

I tried to handle this by catching the SIM PIN and automatically
re-sending it after the power up when needed. See
'sierra-pin-after-power-up' branch in git. But, then I got to the next
problem:

2) The modem is not reliable at all. Lots of times, CFUN=1,0 really ends
up resetting the modem while we're waiting for the OK reply. Fixing the
lock after power-up is only meaningful if the modem really always
powers-up without reset in CFUN=1,0.

So, I ended up disabling CFUN=4 in a branch and retrying with that. Of
course if CFUN=1 when the modem powers up, we wouldn't need to
re-power-up and all the issues before would go away. But no...

3) In the lucky cases where CFUN=1,0 doesn't reset, or if CFUN=4 is
removed, the modem may or may not end up resetting afterwards after some
other command (e.g. listing SMS).

Not sure if I should try to update the firmware of the modem, or
directly re-sell it :-). My current firmware revision is:
'J1_0_1_6AP C:/WS/FW/J1_0_1_6AP/MSM7200A/SRC/AMSS 2008/07/09 07:52:58'

Thoughts?

-- 
Aleksander