On Thu, 8 Apr 2010, hermann pitton wrote: > Hi, > > Am Mittwoch, den 07.04.2010, 20:50 +0200 schrieb Lars Hanisch: > > Am 06.04.2010 16:33, schrieb Mike Isely: > [snip] > > >> > > >> Mike, do you know of anyone actively using that additional information? > > > > > > Yes. > > > > > > The VDR project at one time implemented a plugin to directly interface > > > to the pvrusb2 driver in this manner. I do not know if it is still > > > being used since I don't maintain that plugin. > > > > Just FYI: > > The PVR USB2 device is now handled by the pvrinput-plugin, which uses only ioctls. The "old" pvrusb2-plugin is obsolete. > > > > http://projects.vdr-developer.org/projects/show/plg-pvrinput Lars: Thanks for letting me know about that - until this message I had no idea if VDR was still using that interface. > > > > Regards, > > Lars. > > [snip] > > thanks Lars. > > Mike is really caring and went out for even any most obscure tuner bit > to help to improve such stuff in the past, when we have been without any > data sheets. Hermann: You might have me confused with Mike Krufky there - he's the one who did so much of the tuner driver overhauling in v4l-dvb in the past. > > To open second, maybe third and even forth ways for apps to use a > device, likely going out of sync soon, does only load maintenance work > without real gain. Well it was an experiment at the time to see how well such a concept would work. I had done it in a way to minimize maintenance load going forward. On both counts I feel the interface actually has done very well, nonstandard though it may be. I still get the general impression that the user community really has liked the sysfs interface, but the developers never really got very fond of it :-( > > We should stay sharp to discover something others don't want to let us > know about. All other ideas about markets are illusions. Or? > > So, debugfs sounds much better than sysfs for my taste. > > Any app and any driver, going out of sync on the latter, will remind us > that backward compat _must always be guaranteed_ ... > > Or did change anything on that and is sysfs excluded from that rule? Backwards compatibility is very important and thus any kind of new interface deserves a lot of forethought to ensure that choices are made in the present that people will regret in the future. Making an interface self-describing is one way that helps with compatibility: if the app can discover on its own how to use the interface then it can adapt to interface changes in the future. I think a lot of people get their brains so wrapped around the "ioctl-way" of doing things and then they try to map that concept into a sysfs-like (or debugfs-like) abstraction that they don't see how to naturally take advantage of what is possible there. -Mike -- Mike Isely isely @ isely (dot) net PGP: 03 54 43 4D 75 E5 CC 92 71 16 01 E2 B5 F5 C1 E8 -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
