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

David Henningsson david.henningsson at canonical.com
Wed Feb 19 20:40:43 CET 2014

On 02/19/2014 03:57 PM, Takashi Sakamoto wrote:
> Hi 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?

I've never heard of it before. I had a quick look in alsa-lib and
couldn't find any difference in handling between CLASS_GENERIC and

It's probably something historic that nobody uses any more. Maybe people
who have been along longer knows what it is.

David Henningsson, Canonical Ltd.

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