Re: [PATCH 1/3] IR: add core lirc device interface

["David Härdeman" <david@hardeman.nu>]

On Fri, Jun 04, 2010 at 03:38:35PM -0300, Mauro Carvalho Chehab wrote:
> Em 04-06-2010 12:51, Christoph Bartelmus escreveu:
> > Hi Mauro,
> > 
> > on 04 Jun 10 at 01:10, Mauro Carvalho Chehab wrote:
> >> Em 03-06-2010 19:06, Jarod Wilson escreveu:
> > [...]
> >>> As for the compat bits... I actually pulled them out of the Fedora kernel
> >>> and userspace for a while, and there were only a few people who really ran
> >>> into issues with it, but I think if the new userspace and kernel are rolled
> >>> out at the same time in a new distro release (i.e., Fedora 14, in our
> >>> particular case), it should be mostly transparent to users.
> > 
> >> For sure this will happen on all distros that follows upstream: they'll
> >> update lirc to fulfill the minimal requirement at Documentation/Changes.
> >>
> >> The issue will appear only to people that manually compile kernel and lirc.
> >> Those users are likely smart enough to upgrade to a newer lirc version if
> >> they notice a trouble, and to check at the forums.
> > 
> >>> Christoph
> >>> wasn't a fan of the change, and actually asked me to revert it, so I'm
> >>> cc'ing him here for further feedback, but I'm inclined to say that if this
> >>> is the price we pay to get upstream, so be it.
> > 
> >> I understand Christoph view, but I think that having to deal with compat
> >> stuff forever is a high price to pay, as the impact of this change is
> >> transitory and shouldn't be hard to deal with.
> > 
> > I'm not against doing this change, but it has to be coordinated between  
> > drivers and user-space.
> > Just changing lirc.h is not enough. You also have to change all user-space  
> > applications that use the affected ioctls to use the correct types.
> > That's what Jarod did not address last time so I asked him to revert the  
> > change.
> 
> For sure coordination between kernel and userspace is very important. I'm sure
> that Jarod can help with this sync. Also, after having the changes implemented
> on userspace, I expect one patch from you adding the minimal lirc requirement 
> at Documentation/Changes.
> 
> > And I'd also like to collect all other change request to the API  
> > if there are any and do all changes in one go.
> 
> You and Jarod are the most indicated people to point for such needs. Also, Jon
> and David may have some comments.

David (who has been absent, sorry about that, life got in the way) 
thinks that the lirc raw decoder should implement the minimum amount of 
ioctl's possible while still being usable by the lirc userspace and 
without going beyond being a raw pulse/space "decoder" or we'll risk 
having to extend the entire decoder API just to support the lirc 
compatability decoder.

Over time, I hope that rc-core will grow it's own chardev with a clean 
set of ioctls (or sysfs controls, the jury hasn't returned a verdict 
yet). lircd can then be upgraded to support both the in-kernel native 
mode and the legacy lirc mode, and with time, the lirc raw decoder can 
be phased out.


-- 
David Härdeman