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authorJussi Laako <jussi@sonarnerd.net>2019-02-18 00:17:21 +0200
committerTakashi Iwai <tiwai@suse.de>2019-02-18 09:36:09 +0100
commitc7a13264918b9796f80c634f20fea56e1612572d (patch)
treed0d8757c02033712f513904f827962e0b0c3fded
parenta06702ca023feccb7c1a5171987f5cac959427ed (diff)
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ALSA: usb-audio: Expose sample resolution through proc interface
At least some USB devices use (MSB-aligned) audio format larger than the actual resolution of the device. In order to expose the actual device resolution (bBitResolution), add extra field to the procfs stream info interface. Signed-off-by: Jussi Laako <jussi@sonarnerd.net> Signed-off-by: Takashi Iwai <tiwai@suse.de>
-rw-r--r--sound/usb/card.h1
-rw-r--r--sound/usb/format.c2
-rw-r--r--sound/usb/proc.c1
3 files changed, 4 insertions, 0 deletions
diff --git a/sound/usb/card.h b/sound/usb/card.h
index ac785d15ced4..79fa2a19fb7b 100644
--- a/sound/usb/card.h
+++ b/sound/usb/card.h
@@ -14,6 +14,7 @@ struct audioformat {
u64 formats; /* ALSA format bits */
unsigned int channels; /* # channels */
unsigned int fmt_type; /* USB audio format type (1-3) */
+ unsigned int fmt_bits; /* number of significant bits */
unsigned int frame_size; /* samples per frame for non-audio */
int iface; /* interface number */
unsigned char altsetting; /* corresponding alternate setting */
diff --git a/sound/usb/format.c b/sound/usb/format.c
index fd13ac11b136..3ee7d6f853b7 100644
--- a/sound/usb/format.c
+++ b/sound/usb/format.c
@@ -87,6 +87,8 @@ static u64 parse_audio_format_i_type(struct snd_usb_audio *chip,
}
}
+ fp->fmt_bits = sample_width;
+
if ((pcm_formats == 0) &&
(format == 0 || format == (1 << UAC_FORMAT_TYPE_I_UNDEFINED))) {
/* some devices don't define this correctly... */
diff --git a/sound/usb/proc.c b/sound/usb/proc.c
index e80c9d0749c9..ef9190530fd2 100644
--- a/sound/usb/proc.c
+++ b/sound/usb/proc.c
@@ -109,6 +109,7 @@ static void proc_dump_substream_formats(struct snd_usb_substream *subs, struct s
if (subs->speed != USB_SPEED_FULL)
snd_iprintf(buffer, " Data packet interval: %d us\n",
125 * (1 << fp->datainterval));
+ snd_iprintf(buffer, " Bits: %d\n", fp->fmt_bits);
// snd_iprintf(buffer, " Max Packet Size = %d\n", fp->maxpacksize);
// snd_iprintf(buffer, " EP Attribute = %#x\n", fp->attributes);
}