Re: ModemManager: power-up/power-down fixes for Wavecom, Cinterion and Sierra modems

[Dan Williams <dcbw redhat com>]

On Wed, 2011-06-22 at 16:35 +0200, Aleksander Morgado wrote:
> Hi all,
> 
> Some fixes related to power-up/power-down some modems are available in
> the 'power-up-check-needed' branch in the following Gitorious repo
> [1]:   
>   git://gitorious.org/lanedo/modemmanager.git

These all look good.  I think in the future though we should just define
some stuff on the Modem object for generic power states that roughly
correspond to the CFUN numbers, ie [OFF, MIN, RF_OFF, FULL] and let
modems handle that as need to.  On startup we'd ask for the modem's
power state which the plugin would return as one of these enums and then
the MM core does what it needs to.  When the core wants to change power
state (ex as a result of Enable()) it'll just tell the plugin to go to
FULL and the plugin translates that to whatever it needs to do.
Thoughts?  I'm just worried about making the power state selection more
complicated with the POWER_UP_CMD properties and stuff and I think this
is actually a clearer, simpler solution which we should have done in the
first place.

But for now please push when you have time.

Dan

> The changes being:
> 
>  * Modified the generic GSM implementation so that we allow plugins to
> check whether they need a power-up command. If plugins reply saying they
> don't need it, the power-up command is skipped.
>  * Added a new property in the Serial Port object to (try to) enable
> RTS/CTS flow control mode in the serial line.
> 
>  * Wavecom: Check whether the modem is in full-functionality mode (AT
> +CFUN: 1), and if so, avoid sending the power-up command.
>  * Wavecom: Use AT+CFUN=4 to go to standby/low-power mode.
>  * Wavecom: Use AT+CFUN=1,0 to power-up the modem (only when not already
> in full functionality mode)
> 
>  * Sierra: Check whether the modem is in full-functionality mode (AT
> +CFUN: 1), and if so, avoid sending the power-up command. This should
> fix LP#459052 [2], which was also reported and discussed in the list not
> long ago [3].
> 
>  * Cinterion: Use AT+CFUN=4 or AT+CFUN=7 to go to standby/low-power
> mode, depending on the supported methods.
>  * Cinterion: Always try to use RTS/CTS flow control in the serial line,
> so that waking up from standby mode works properly.
> 
> 
> Cheers!
> 
> [1] https://gitorious.org/lanedo/modemmanager
> [2] https://bugs.launchpad.net/ubuntu/+source/modemmanager/+bug/459052
> [3]
> https://mail.gnome.org/archives/networkmanager-list/2011-May/msg00150.html
> 
>