ALSA: snd-usb: handle raw data format of UAC2 devices

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@gmail.com>
Reported-by: Andreas Koch <andreas@akdesigninc.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

1 files changed, 7 insertions, 4 deletions

diff --git a/sound/usb/format.c b/sound/usb/format.c
index b30d6fb89b40..a695cafc0599 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);