HAL, new things

[David Zeuthen]

Hi Richard,

Initially you wrote:
> Okay, with the release of HAL 0.5.4, HAL can do a whole lot more.
> These are the things that I think we *can* do from here, but maybe
> you'll have feedback on what we *should* do.

Hmm.. At least following the #gnome-hackers IRC channel on GimpNet it
appears we still got some work left with reporting battery status -
davyd on said channel knows the specifics. So it would be good to fix
these before introducing new functionality and bugs :-)

Also, we still have doc/TODO and other mundane stuff left.

On Mon, 2005-08-29 at 11:12 +0100, Richard Hughes wrote:
> On Sun, 2005-08-28 at 21:42 -0400, Bill Nottingham wrote:
> > Richard Hughes (hughsient at gmail.com) said: 
> > > * Video Adaptor support, i.e. a SetLCDBrighness() method on applicable
> > > laptops.
> > 
> > Considering the wonderful interfaces the kernel exports for this, the backend's
> > going to be gross.
> 
> Sure, but we can make the backend hacky in HAL and present a nice
> interface to the user, (that-is until we get a nice sysfs interface for
> video adaptors, and then we can use that). Even if we get toshiba, asus
> and ibm working, that's a large percentage.

Yes, I think we should do something like this. At some point there will
be either

 o a sysfs interface which may or may not be vendor specific

 o some interface to the currently non-existing mode settings daemon /
   library 

 o something else

I don't really care much what the interface is, just that we can do what
we want with it. There's also the side-effect that if we export a sane
interface from hal, driver writes will want to customize their
implementations towards it... 

So, I'd say we just go ahead and create this interface - we can always
change it once the kernel/X.org driver side is more hashed out - either
way, it's better to write code than sit and talk about it for months on
mailing lists :-)

> > > * Device firmware request: i.e. if I insert my spiffy atmel 802.11b
> > > pcmcia card, HAL tells me (dbus signal to notification-daemon?) I need
> > > firmware before the device will work. Similar if I insert my friends
> > > NTFS usb pendrive. Also it would be nice to know if I could look at a
> > > website and get some info about a driver from CVS.
> > 
> > Where would you get the notification that the firmware load failed? Do you
> > want this code in the udev firmware helper, to send a d-bus signal with
> > the filename when firmware load fails? Or somewhere else?

Need to consider 

 a. what interface we want to export from hal

 b. how to implement this

but my gut feeling is that the kernel doesn't yet export a sane
interface. You really have to figure out the contents of a. too before
doing that.

> Not sure, hence opening the discussion. :-) My initial thought was to
> use notification-daemon, but that is a session DBUS service, whilst HAL
> is per-system. Not sure if that would work - either way we need a way
> for HAL to pop-up a box saying

You're mixing matters here which is slightly confusing; you probably
mean you want some desktop program running in the session (like
gnome-volume-manager) that reacts to events from HAL and does the right
thing.

>  "You have a device that would work, if
> you install the required firmware" (IANAL: never mentioning where to get
> the firmware in question, cough, livna, cough :-)

IANAL either but I think this is OK.

Cheers,
David