Re: ZTE modem problems and workrounds

[Dan Williams <dcbw redhat com>]

On Wed, 2009-07-01 at 19:43 +0100, Rick Jones wrote:
> --On Wednesday, July 01, 2009 14:36:24 -0400 Dan Williams
> <dcbw redhat com> wrote:
> > > Functionality is definitely tied to the IF number. IF0 is
> effectively
> > > dead (supposedly NMEA, but I don't know what it's meant to
> support).
> > > IF1 & IF3 both behave like a modem (usually), and seem very
> closely
> > > tied together. E.g. if you use ATE0 to turn off echo on one port,
> it
> > > is turned off on both. Very occasionally, IF1 will not respond to
> AT
> > > commands, but the modem still works on the correct IF3 port, and
> IF1
> > > still spits out messages.
> > 
> > How often does IF1 spit out messages?  What do they look like?
> 
> The messages all come out the same on both IF! & IF3, regardless of
> whether IF1 decides to accept commands.
> 
> To start with there is always +ZUSIMR:2 every 2 secs., this can be
> stopped by giving any version of AT+CPMS on either port (stops the
> messages on both ports). The only other UMs I see are +ZDONR and
> +ZPASR.

Ugh.  That sucks.  That means hardcoding stuff on a per-modem basis,
potentially using AT+CGMM responses instead of USB IDs, because some
vendors (Huawei) use the same USB ID for vastly different devices to
work around stupid Windows bugs.

Dan