Re: Novatel based Mobile Broadband does not respond anymore

[Dan Williams <dcbw redhat com>]

On Thu, 2012-01-26 at 16:13 +0100, richter ecos de wrote:
> Hi,
> 
> we've problems with a Novatel based Mobile Broadband card.
> 
> The serial device doesn't respond to AT Commands after it has been
> initialized and a successfully registration to an apn.
> The modem-manager falls back in an endless loop after that behavior.
> 
> Bus 004 Device 002: ID 413c:8137 Dell Computer Corp. Wireless 5520 Voda L
> Mobile Broadband (3G HSDPA) Minicard Status Port
> 
> The logfile is attached.
> 
> Before we used network manager, we had a very simply umts solution, which only uses a few AT commands. This did work for quite a long time.
> 
> It seems that the firmware crashes on some of the AT command (coldstart is necessary, to get the card working again).
> 
> Any ideas?

I've seen the firmware of my 5510 (which is basically the EU870D except
in ExpressCard form) crash when doing SMS-related stuff.  If you're able
to rebuild ModemManager, try this patch and see if that helps anything:

diff --git a/src/mm-generic-gsm.c b/src/mm-generic-gsm.c
index 3a1c62e..be63d97 100644
--- a/src/mm-generic-gsm.c
+++ b/src/mm-generic-gsm.c
@@ -1260,10 +1260,10 @@ enable_failed (MMModem *modem, GError *error, MMCallbackInfo *info)
 }
 
 static guint32 best_charsets[] = {
+    MM_MODEM_CHARSET_IRA,
     MM_MODEM_CHARSET_UTF8,
     MM_MODEM_CHARSET_UCS2,
     MM_MODEM_CHARSET_8859_1,
-    MM_MODEM_CHARSET_IRA,
     MM_MODEM_CHARSET_GSM,
     MM_MODEM_CHARSET_UNKNOWN
 };

Some modems don't deal well with UCS2 and my 5510 is one of them.  The
charset doesn't just affect SMS so it might be causing the crashes.

Dan