Video and Keymap Quirks

[Michael E Brown]

On Thu, Jul 12, 2007 at 09:20:56PM +0100, Richard Hughes wrote:
> On Thu, 2007-07-12 at 13:00 -0500, Michael E Brown wrote:
> > I havent had a lot of time to pursue it, but I have seen several people
> > working on things to handle killswitches. The problem I've seen is that
> > several of them dont take into account features that the Dell notebooks
> > have: software configurable killswitches, and killswitch for cellular in
> > particular. 
> 
> Why do we need to configure a killswitch? Surely a kill switch is just
> something that kills _all_ wireless for aircraft. If you want to power
> down individual devices surely this should be done in sysfs.

The word "surely" implies policy. The dell implementation provides
mechanism, the user provides policy. Aircraft is one policy.
I'm-sitting-at-starbucks-and-dont-want-somebody-to-hack-my-wireless-
while-I-upload-pictures-from-my-phone-to-my-laptop-over-bluetooth
is another policy. The user can decide which policy they want the
killswitch to provide via either BIOS configuration options or through
dellWirelessCtl.

Writing software that just assumes that the killswitch can only ever do
an all-or-nothing operation is encoding bad policy in our software.

Also, sysfs, as I've mentioned elsewhere, is a crappy interface for this
specific functionality. dellWirelessCtl is implemented in userspace, and
it doesnt make sense to try to write a kernel module to do it. 

> > > > Recent Dell laptops all have a wireless switch. This switch can be
> > > > configured at runtime by dellWirelessCtl (part of libsmbios-bin) to
> > > > individually turn on/off any combination of each of the above.
> > > 
> > > We could hook this up to HAL (although I'm not sure yet how) but I'm
> > > guessing the most sane thing to do would be to tie it to a hardware
> > > killswitch that killed all the wireless devices for aircraft scenario.
> > 
> > I wrote dellWirelessCtl. There was a patch a while back that integrated
> > it into HAL, but I didnt write that.
> 
> Sure, unless this stuff just works, very few people are going to use it.

At the moment, the HAL guys say that it Just Works (havent tested it
myself).
--
Michael