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| author | Takashi Sakamoto <o-takashi@sakamocchi.jp> | 2017-05-22 15:22:21 +0200 |
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2017-05-22 16:24:08 +0200 |
| commit | a02cb8f8def634159b60c3a4d6ba16e471b46e0c (patch) | |
| tree | d7d6cc26b7747ce434433d9723d1afcc9b7cfc2b /sound/firewire/amdtp-am824.h | |
| parent | ALSA: mixart: constify snd_kcontrol_new structures (diff) | |
| download | linux-a02cb8f8def634159b60c3a4d6ba16e471b46e0c.tar.xz linux-a02cb8f8def634159b60c3a4d6ba16e471b46e0c.zip | |
ALSA: firewire: remove support for 16 bit PCM samples in playback substream
In IEC 61883-6, AM824 is described as format of data block. In this
format, one data block consists of several data channels, which is aligned
to 32 bit. One data channel has 8 bit label field and 24 bit data field.
PCM frames are transferred in Multi Bit Linear Audio (MBLA) data channel.
This channel can include 16/20/24 bit PCM sample.
As long as I know, models which support IEC 61883-1/6 doesn't allow to
switch bit length of PCM sample in MBLA data channel. They always
transmit/receive PCM frames of 24 bit length. This can be seen for the
other models which support protocols similar to IEC 61883-1/6.
On the other hand, current drivers for these protocols supports 16 bit
length PCM sample in playback substream. In this case, PCM sample is put
into the MBLA data channel with 8 bit padding in LSB side. Although 16
bit PCM sample is major because it's in CD format, this doesn't represent
device capability as is.
This commit removes support for 16 bit PCM samples in playback substream.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Acked-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound/firewire/amdtp-am824.h')
| -rw-r--r-- | sound/firewire/amdtp-am824.h | 6 |
1 files changed, 1 insertions, 5 deletions
diff --git a/sound/firewire/amdtp-am824.h b/sound/firewire/amdtp-am824.h index 73b07b3109db..b56e61fc997d 100644 --- a/sound/firewire/amdtp-am824.h +++ b/sound/firewire/amdtp-am824.h @@ -8,8 +8,7 @@ #define AM824_IN_PCM_FORMAT_BITS SNDRV_PCM_FMTBIT_S32 -#define AM824_OUT_PCM_FORMAT_BITS (SNDRV_PCM_FMTBIT_S16 | \ - SNDRV_PCM_FMTBIT_S32) +#define AM824_OUT_PCM_FORMAT_BITS SNDRV_PCM_FMTBIT_S32 /* * This module supports maximum 64 PCM channels for one PCM stream @@ -41,9 +40,6 @@ void amdtp_am824_set_midi_position(struct amdtp_stream *s, int amdtp_am824_add_pcm_hw_constraints(struct amdtp_stream *s, struct snd_pcm_runtime *runtime); -void amdtp_am824_set_pcm_format(struct amdtp_stream *s, - snd_pcm_format_t format); - void amdtp_am824_midi_trigger(struct amdtp_stream *s, unsigned int port, struct snd_rawmidi_substream *midi); |