Re: [PATCH] Add udev rules for HP (Ericsson) hs2350 Mobile Broadband Module

[Dan Williams <dcbw redhat com>]

On Sun, 2012-10-14 at 17:00 +0200, Aleksander Morgado wrote:
> On 10/12/2012 09:53 PM, David Härdeman wrote:
> > I should perhaps add that I've tried using the modem on MM 0.5 and 0.6.
> > 
> > Both seem to have the same three problems:
> > 
> > a) Modem doesn't survive a suspend/resume (can't connect after)
> > 
> > b) USSD command don't work
> > 
> > c) Network operator name isn't shown
> > 
> > Haven't testing the bleeding edge of MM, but I need to be able to use
> > the laptop daily so I'm not really in a position to try that (right
> > now).
> 
> Can you get ModemManager debug logs to see what is happening?

Yeah, certainly MM logs are necessary here.  One problem with
suspend/resume is that modem itself may be de-initialized, but there's
nothing that tells MM that this occurs, indeed nothing in MM listens for
suspend/resume events because typically that's not required.  Usually
the TTYs are closed and on resume MM re-detects the device and sets
things up again.

Some drivers (eg nozomi) don't follow this pattern though, and on resume
it looks like nothing actually happened, except the card is not
initialized but MM still thinks it is.  Thus we may actually need to
listen to upower or systemd suspend/resume events and handle things
appropriately.  That really sucks, since I'm of the opinion the kernel
should just have events like this, but unfortunately it doesn't.  Or
maybe we just need to fix drivers somehow.

Dan

> 
> > 
> > Are these known problems with Ericsson MBM's and might they be fixed in
> > the master branch?
> 
> If the issues are in MM 0.5/0.6 then git master has *at least* those
> issues as well more than probably :-)
>