Re: NetworkManager and rf_kill

[Dan Williams <dcbw redhat com>]

On Tue, 2008-05-06 at 18:08 +0200, Khashayar Naderehvandi wrote:
> Hi list,
> 
> When disabling wireless network using nm-applet, NM does not seem to
> disable the device (by means of /sys/class/net/wlan0/device/rf_kill).
> This is true both of the 0.6.6 version that Ubuntu Hardy ships and a
> quite recent svn build that I've compiled myself. The svn build is on
> a machine with the ipw2200 driver and the 0.6.6 version is on a
> machine which uses the iwlwifi driver on 4965 chipset.
> 
> Is this a bug that I should report, or is it a not yet implemented
> feature?

NetworkManager marks the device as down, ie !IFF_UP.  Devices that are
marked down should enter the lowest possible power saving mode,
unfortunately that's not consistent behavior across drivers.  That's how
power-save works for wired devices and should work for wireless ones.
However, it turns out that there are some parts (iwlwifi for example)
that cannot detect rfkill unless firmware is loaded, which they do only
when the device is up.  To fix that, NM is going to switch to simply
turning off the TX power of the device.

Unfortunately, we need better support from HAL here, since HAL is not
quite verbose enough to tell NM that the radio is hardware-rfkilled or
software-rfkilled, which means NM can't know whether or not you can
re-enable the radio via software or whether the user actually flipped a
switch.

Once that is fixed, I'll flip NM over to turning off TX power and then
it will probably Just Work for you.

dan