> > > Hans Werner schreef: > >>> Now, to show how simple I think all this could be, here is a PATCH > >>> > >> implementing what > >> > >>> I think is the *minimal* API required to support DVB-S2. > >>> > >>> Notes: > >>> > >>> * same API structure, I just added some new enums and variables, > nothing > >>> > >> removed > >> > >>> * no changes required to any existing drivers (v4l-dvb still compiles) > >>> * no changes required to existing applications (just need to be > >>> > >> recompiled) > >> > >>> * no drivers, but I think the HVR4000 MFE patch could be easily > adapted > >>> > >>> I added the fe_caps2 enum because we're running out of bits in the > >>> > >> capabilities bitfield. > >> > >>> More elegant would be to have separate bitfields for FEC capabilities > >>> > >> and modulation > >> > >>> capabilities but that would require (easy) changes to (a lot of) > drivers > >>> > >> and applications. > >> > >>> Why should we not merge something simple like this immediately? This > >>> > >> could have been done > >> > >>> years ago. If it takes several rounds of API upgrades to reach all the > >>> > >> feature people want then > >> > >>> so be it, but a long journey begins with one step. > >>> > >> This will break binary compatibility with existing apps. You're right > >> -- those apps will work with a recompile, but I believe that as a > >> whole, the linux-dvb kernel and userspace developers alike are looking > >> to avoid breaking binary compatibility. > >> > > > > Michael, > > thank you for your comment. > > > > I understand, but I think binary compatibility *should* be broken in > this case. It makes > > everything else simpler. > > > > I know that not breaking binary compatibility *can* be done (as in the > HVR4000 SFE and > > MFE patches) but at what cost? The resulting code is very odd. Look at > multiproto which > > bizarrely implements both the 3.2 and the 3.3 API and a compatibility > layer as well, at huge cost > > in terms of development time and complexity of understanding. The > wrappers used in the MFE > > patches are a neat and simple trick, but not something you would release > in the kernel. > > > > If you take the position the binary interface cannot *ever* change then > you are severely > > restricting the changes that can be made and you doom yourself to an API > that is no longer > > suited to the job. And the complexity kills. As we have seen, it makes > the whole process grind to a > > halt. > > > > Recompilation is not a big deal. All distros recompile every application > for each release (in fact much more frequently -- updates too), so most > users will never even notice. It is much better to make the right, elegant > changes to the API and require a recompilation. It's better for the > application developers because they get a sane evolution of the API and can more > easily add new features. Anyone who > > really cannot recompile existing userspace binaries will also have > plenty of other restrictions and > > should not be trying to drop a new kernel into a fixed userspace. > > > > I would be interested to hear your opinion on how we can move forward > rapidly. > > > > Regards, > > Hans > > > > Jelle De Loecker wrote up there and I moved it down here: -------- Original-Nachricht -------- > Datum: Fri, 29 Aug 2008 18:50:23 +0200 > Von: Jelle De Loecker <skerit@xxxxxxxxxxx> > An: linux-dvb@xxxxxxxxxxx > Betreff: Re: [PATCH] Future of DVB-S2 > I wasn't really focusing the haupage drivers, more the multiproto > drivers manu created. > > I have a TT S2-3200. > > You're talking about upcoming change in the HVR4000 world? Do you know > anything about our little technotrend cards? > > /Met vriendelijke groeten,/ > > *Jelle De Loecker* > Kipdola Studios - Tomberg > Jelle, yes I know you're interested in the TT S2-3200, but the issues are the same for all the DVB-S2 cards (which are already numerous and popular). There is a multiproto driver for the HVR4000 too, but in addition there are some drivers written by Steven and Darron which take different (and illuminating) approaches to providing DVB-S2 support. Once the issues blocking DVB-S2 support in the kernel are sorted out we should hope that all the out-of-kernel DVB-S2 drivers will move into the kernel quickly, including the TT S2-3200 driver. We need to break the deadlock as soon as possible. Hans -- Release early, release often. Really, you should GMX startet ShortView.de. Hier findest Du Leute mit Deinen Interessen! Jetzt dabei sein: http://www.shortview.de/wasistshortview.php?mc=sv_ext_mf@gmx _______________________________________________ linux-dvb mailing list linux-dvb@xxxxxxxxxxx http://www.linuxtv.org/cgi-bin/mailman/listinfo/linux-dvb
