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ALSA: aloop: Introduce a function to get if access is interleaved mode 

[ Upstream commit cdac6e1f71 ]

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: 462494565c ("ALSA: aloop: Add support for the non-interleaved access mode")
Signed-off-by: Chancel Liu <chancel.liu@nxp.com>
Link: https://lore.kernel.org/r/20240111025219.2678764-1-chancel.liu@nxp.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Chancel Liu 2024-01-11 11:52:19 +09:00 committed by Greg Kroah-Hartman
parent aec366faed
commit 86778b7b9f
1 changed files with 17 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

23
sound/drivers/aloop.c
View File

@ -322,6 +322,17 @@ static int loopback_snd_timer_close_cable(struct loopback_pcm *dpcm)
return 0;
}
static bool is_access_interleaved(snd_pcm_access_t access)
{
switch (access) {
case SNDRV_PCM_ACCESS_MMAP_INTERLEAVED:
case SNDRV_PCM_ACCESS_RW_INTERLEAVED:
return true;
default:
return false;
}
};
static int loopback_check_format(struct loopback_cable *cable, int stream)
{
struct snd_pcm_runtime *runtime, *cruntime;
@ -341,7 +352,8 @@ static int loopback_check_format(struct loopback_cable *cable, int stream)
check = runtime->format != cruntime->format ||
runtime->rate != cruntime->rate ||
runtime->channels != cruntime->channels ||
runtime->access != cruntime->access;
is_access_interleaved(runtime->access) !=
is_access_interleaved(cruntime->access);
if (!check)
return 0;
if (stream == SNDRV_PCM_STREAM_CAPTURE) {
@ -369,7 +381,8 @@ static int loopback_check_format(struct loopback_cable *cable, int stream)
&setup->channels_id);
setup->channels = runtime->channels;
}
if (setup->access != runtime->access) {
if (is_access_interleaved(setup->access) !=
is_access_interleaved(runtime->access)) {
snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE,
&setup->access_id);
setup->access = runtime->access;
@ -584,8 +597,7 @@ static void copy_play_buf(struct loopback_pcm *play,
size = play->pcm_buffer_size - src_off;
if (dst_off + size > capt->pcm_buffer_size)
size = capt->pcm_buffer_size - dst_off;
if (runtime->access == SNDRV_PCM_ACCESS_RW_NONINTERLEAVED ||
runtime->access == SNDRV_PCM_ACCESS_MMAP_NONINTERLEAVED)
if (!is_access_interleaved(runtime->access))
copy_play_buf_part_n(play, capt, size, src_off, dst_off);
else
memcpy(dst + dst_off, src + src_off, size);
@ -1544,8 +1556,7 @@ static int loopback_access_get(struct snd_kcontrol *kcontrol,
mutex_lock(&loopback->cable_lock);
access = loopback->setup[kcontrol->id.subdevice][kcontrol->id.device].access;
ucontrol->value.enumerated.item[0] = access == SNDRV_PCM_ACCESS_RW_NONINTERLEAVED ||
access == SNDRV_PCM_ACCESS_MMAP_NONINTERLEAVED;
ucontrol->value.enumerated.item[0] = !is_access_interleaved(access);
mutex_unlock(&loopback->cable_lock);
return 0;