I think this issue has nothing to do with subsystems, anyway, both are acceptable to me. Since there has been an example in ASoC, I will follow it and send v2. thanks -barry On Fri, Mar 19, 2010 at 2:08 AM, Mike Frysinger <vapier.adi@xxxxxxxxx> wrote: > On Thu, Mar 18, 2010 at 14:05, Mark Brown wrote: >> On Thu, Mar 18, 2010 at 01:17:11PM -0400, Mike Frysinger wrote: >>> > The subsystem dependency here come from the fact that ASoC has machine >>> > drivers and relies on them selecting the CODEC drivers to get them built >>> > in the first place so if you're trying to change something like this >>> > you'll most likely not only have to rebuild your kernel but also have to >>> > write code. This isn't something that the input layer has (input layer >>> > drivers are pretty much standalone, usually only need platform data >>> > for any per machine hookup and for I2C and SPI can even be registered >>> > from user space IIRC) and it changes the considerations noticably. >> >>> the machine driver selects the codec, it doesnt select the bus. the >>> codec worries about that. so i dont quite follow the logic here. >> >> That's not the case, CODEC drivers do absolutely nothing to ensure that >> they have the buses they need. Multi bus CODECs should all be perfectly >> happy to build with no bus at all, though sparse and/or GCC will warn. >> >> Kconfig will cheerfully ignore any dependencies of things that are >> selected - unless it's been updated recently all a select does is force >> the selected symbol on, it doesn't recurse through dependencies and >> selects of that symbol. Besides, multi bus CODEC drivers can't know >> which of their possible buses are actually needed on a given system - >> they just build support for any bus types that are configured and let >> something else worry about the resulting configuration actually being >> useful. > > sure, on the Kconfig side, i can see that. i was thinking the pure C > drivers though. thanks for the clarification. > -mike > _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
