Re: [PATCH 2/5] ALSA: usb-audio: unify UAC macros and struct names

[Daniel Mack <daniel@caiaq.de>]

On Wed, Jun 16, 2010 at 01:31:17PM -0700, Alex Lee wrote:
> It will be painful, but what about defining a whole new set of
> UAC2_xxx constants even if it is the same value as UAC1 ?

That doesn't really help much, as the code using these macros is hybrid,
for both versions. Just grep for them in the sources to see what I mean
:)

Daniel


> On 16-Jun-2010, at 1:21 PM, Takashi Iwai <tiwai@suse.de> wrote:
> 
> >At Wed, 16 Jun 2010 19:40:44 +0200,
> >Daniel Mack wrote:
> >>
> >>On Wed, Jun 16, 2010 at 07:34:49PM +0200, Takashi Iwai wrote:
> >>>At Wed, 16 Jun 2010 17:57:28 +0200,
> >>>Daniel Mack wrote:
> >>>>
> >>>>diff --git a/include/linux/usb/audio.h b/include/linux/usb/audio.h
> >>>>index c51200c..a54b825 100644
> >>>>--- a/include/linux/usb/audio.h
> >>>>+++ b/include/linux/usb/audio.h
> >>>>@@ -39,8 +39,8 @@
> >>>>#define UAC_MIXER_UNIT            0x04
> >>>>#define UAC_SELECTOR_UNIT        0x05
> >>>>#define UAC_FEATURE_UNIT        0x06
> >>>>-#define UAC_PROCESSING_UNIT_V1        0x07
> >>>>-#define UAC_EXTENSION_UNIT_V1        0x08
> >>>>+#define UAC1_PROCESSING_UNIT        0x07
> >>>>+#define UAC1_EXTENSION_UNIT        0x08
> >>>
> >>>So now we have mixed prefix here, UAC_ and UAC1_.
> >>>Isn't it a bit confusing, too?
> >>>
> >>>Honestly, I have no much preference about this name-ruling.
> >>>But it's of course better if it's stabilized :)
> >>
> >>Well yeah, I hate that too, especially as it is a matter of taste
> >>eventually.
> >
> >Indeed, it's just a matter of taste.
> >
> >>However, the idea is: things that are common for both UAC1
> >>and UAC2 are prefixed with UAC_, and only those things that are
> >>special
> >>get a number suffix. Which is the case in the block you quoted above.
> >
> >Yeah, that I understood.  It's just that I feel something not clear
> >around this...  It might be simply because of the salad I ate today,
> >though.  But I'd like to hear opinions of others before merging.
> >If nothing comes up, I'm willing to apply as is.
> >
> >>(This perticular detail is really the greatest unnecessary
> >>confusion in
> >>the UAC2 spec, btw. They just drop one enumeration value and shuffled
> >>two others around for no obvious reason. Now we have to live
> >>with that.)
> >
> >There are always enough examples how to behave rude :)
> >
> >
> >thanks,
> >
> >Takashi