On 10/22/2013 09:01 PM, Thierry Reding wrote:

On Tue, Oct 22, 2013 at 05:34:45PM +0200, Jean-Christophe
PLAGNIOL-VILLARD wrote:

...

quoted

I'm sorry but the blacklight descibe in DT have nothing to do
with the common pratice that the current driver have today

That's not at all what I said. What I said was that the majority
of backlight drivers currently default to turning the backlight on
when probed. Therefore I think it would be consistent if this
driver did the same.

I also said that I don't think it's a very good default, but at the
same time we can't just go and change the default behaviour at will
because people may rely on it.

It may well be reasonable to change the default behaviour for devices
instantiated from DT. If it's not possible to instantiate the device
from DT yet, then it's not possible for anyone to be relying on the
default behaviour yet, since there is none. So, perhaps the default
could be:

* If device instantiated from a board file, default to on, for
backwards-compatibility.

* If device instantiated from DT, there is no backwards compatibility
to be concerned with, since this is a new feature, hence default to
off, since we think that's the correct thing to do.