[alsa-devel] About 'SNDRV_PCM_CLASS_MULTI' for devices with multi-channels

Takashi Iwai tiwai at suse.de
Thu Feb 20 09:02:18 CET 2014

At Thu, 20 Feb 2014 11:28:48 +0900,
Takashi Sakamoto wrote:
> Hi David,
> (My message was not delivered by ALSA's mailman...)

Because you posted from an address that isn't subscribed.
It takes time until manually approved.

> Again all,
>  >> I have two questions about the usage of this macro.
>  >>
>  >> Should I use this macro for new drivers which I'm working for?'
>  >> 
> http://mailman.alsa-project.org/pipermail/alsa-devel/2014-January/071820.html
>  >>
>  >>
>  >> My drivers support some firewire devices, which is desinged for
>  >> studio-use and have many channels. Its combination of channels are not
>  >> designed for surround sound like 5.1ch.
>  >>
>  >> Just judging from its name, 'SNDRV_PCM_CLASS_MULTI', I should use this.
>  >> But there are no drivers which use this macro in current tree, against
>  >> my expectation that some drivers (ICE1712-pro, RME9652, 6fire usb and so
>  >> on) should use this macro.
>  >>
>  >> Are there any reasons?
> In current tree, there are no drivers which uses this macro.
> As long as I investigated in ftp server, this macro is firstly added in 
> ALSA 0.9.0beta1 (2001/02/21). So this macro has been ignored over 10 
> years...

Right.  And the likely reason is that such a differentiation doesn't
help much.  You can still use your device for driving 5.1 surround :)

So, I rather would like to keep them RIP.  Maybe worth to remove it


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