UAC2 compliant audio devices may announce the capability to transport
raw audio data on their endpoints. Catch this and handle it as
'special' stream on the ALSA side.
Signed-off-by: Daniel Mack <zonque@xxxxxxxxx>
Reported-by: Andreas Koch <andreas@xxxxxxxxxxxxxxx>
---
include/linux/usb/audio-v2.h | 2 ++
sound/usb/format.c | 11 +++++++----
2 files changed, 9 insertions(+), 4 deletions(-)
diff --git a/include/linux/usb/audio-v2.h b/include/linux/usb/audio-v2.h
index ed13053..c5f2158 100644
--- a/include/linux/usb/audio-v2.h
+++ b/include/linux/usb/audio-v2.h
@@ -170,6 +170,8 @@ struct uac2_as_header_descriptor {
__u8 iChannelNames;
} __attribute__((packed));
+#define UAC2_FORMAT_TYPE_I_RAW_DATA (1 << 31)
+
/* 4.10.1.2 Class-Specific AS Isochronous Audio Data Endpoint Descriptor */
struct uac2_iso_endpoint_descriptor {
diff --git a/sound/usb/format.c b/sound/usb/format.c
index b30d6fb..a695caf 100644
--- a/sound/usb/format.c
+++ b/sound/usb/format.c
@@ -47,7 +47,7 @@ static u64 parse_audio_format_i_type(struct snd_usb_audio *chip,
int protocol)
{
int sample_width, sample_bytes;
- u64 pcm_formats;
+ u64 pcm_formats = 0;
switch (protocol) {
case UAC_VERSION_1:
@@ -63,14 +63,17 @@ static u64 parse_audio_format_i_type(struct snd_usb_audio *chip,
struct uac_format_type_i_ext_descriptor *fmt = _fmt;
sample_width = fmt->bBitResolution;
sample_bytes = fmt->bSubslotSize;
+
+ if (format & UAC2_FORMAT_TYPE_I_RAW_DATA)
+ pcm_formats |= SNDRV_PCM_FMTBIT_SPECIAL;
+
format <<= 1;
break;
}
}
- pcm_formats = 0;
-
- if (format == 0 || format == (1 << UAC_FORMAT_TYPE_I_UNDEFINED)) {
+ if ((pcm_formats == 0) &&
+ (format == 0 || format == (1 << UAC_FORMAT_TYPE_I_UNDEFINED))) {
/* some devices don't define this correctly... */
snd_printdd(KERN_INFO "%d:%u:%d : format type 0 is detected, processed as PCM\n",
chip->dev->devnum, fp->iface, fp->altsetting);
--
1.7.10.4
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