Re: [PATCH] ALSA: aloop: Introduce a function to get if access is interleaved mode

[Takashi Iwai <tiwai@suse.de>]

On Thu, 11 Jan 2024 03:52:19 +0100,
Chancel Liu wrote:
> 
> There's a use case that playback stream of a loopback cable works on
> RW_INTERLEAVED mode while capture stream works on MMAP_INTERLEAVED mode:
> 
> aplay -Dhw:Loopback,0,0 S32_48K_2ch.wav;
> arecord -Dplughw:Loopback,1,0 -fS32_LE -r16000 -c2 cap.wav;
> 
> The plug plugin handles only slave PCM support MMAP mode. Not only plug
> plugin but also other plugins like direct plugins(dmix/dsnoop/dshare)
> work on MMAP access mode. In this case capture stream is the slave
> PCM works on MMAP_INTERLEAVED mode. However loopback_check_format()
> rejects this access setting and return:
> 
> arecord: pcm_read:2240: read error: Input/output error
> 
> To fix it a function called is_access_interleaved() is introduced to
> get if access is interleaved mode. If both access of capture stream and
> playback stream is interleaved mode loopback_check_format() will allow
> this kind of access setting.
> 
> Fixes: 462494565c27 ("ALSA: aloop: Add support for the non-interleaved access mode")
> Signed-off-by: Chancel Liu <chancel.liu@nxp.com>

Applied now.  Thanks.


Takashi