Re: [RFT 3/4] cfg80211: add rfkill support

[Marcel Holtmann <marcel@holtmann.org>]

Hi Dan,

> > plain text document attachment (015-cfg80211-rfkill.patch)
> > To be easier on drivers and users, have cfg80211 register an
> > rfkill structure that drivers can access. When soft-killed,
> > simply take down all interfaces; when hard-killed the driver
> > needs to notify us and we will take down the interfaces
> > after the fact. While rfkilled, interfaces cannot be set UP.
> 
> Any chance we could get something other than EINVAL returned from the
> PRE_UP notifier when the device is rfkilled?  It's useful to get some
> indication of *why* the device can't be brought up.  For example, if the
> device requires firmware but that firmware isn't present, the driver
> will usually return ENOENT because that's what request_firmware()
> returns when it can't find what it needs.  Thus userspace can do
> something intelligent with the error.
> 
> So maybe EL2HLT could be (ab)used here?  I guess technically it's an L1
> halt since the PHY is powered down, but whatever.  The only other stuff
> that seems to use this are the USB 'gadget' drivers.  Either that, or
> lets make an EL1OFF or ERFKILL maybe.

I think that creating ERFKILL is a really good idea. We should do that.

Regards

Marcel