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| author | Calvin Owens <jcalvinowens@gmail.com> | 2013-04-12 22:33:59 -0500 |
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2013-04-13 10:58:03 +0200 |
| commit | 1539d4f82ad534431cc67935e8e442ccf107d17d (patch) | |
| tree | edb34bea8a89d757f14bbf099329285c036f7279 /sound/usb/card.h | |
| parent | b26b51166848758d740ab638fc27789228a51c97 (diff) | |
| download | lwn-1539d4f82ad534431cc67935e8e442ccf107d17d.tar.gz lwn-1539d4f82ad534431cc67935e8e442ccf107d17d.zip | |
ALSA: usb: Add quirk for 192KHz recording on E-Mu devices
When recording at 176.2KHz or 192Khz, the device adds a 32-bit length
header to the capture packets, which obviously needs to be ignored for
recording to work properly.
Userspace expected: L0 L1 L2 R0 R1 R2
...but actually got: R2 L0 L1 L2 R0 R1
Also, the last byte of the length header being interpreted as L0 of
the first sample caused spikes every 0.5ms, resulting in a loud 16KHz
tone (about the highest 'B' on a piano) being present throughout
captures.
Tested at all sample rates on an E-Mu 0404USB, and tested for
regressions on a generic USB headset.
Signed-off-by: Calvin Owens <jcalvinowens@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound/usb/card.h')
| -rw-r--r-- | sound/usb/card.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/sound/usb/card.h b/sound/usb/card.h index 8a751b4887ea..d32ea411545a 100644 --- a/sound/usb/card.h +++ b/sound/usb/card.h @@ -116,6 +116,7 @@ struct snd_usb_substream { unsigned int altset_idx; /* USB data format: index of alternate setting */ unsigned int txfr_quirk:1; /* allow sub-frame alignment */ unsigned int fmt_type; /* USB audio format type (1-3) */ + unsigned int pkt_offset_adj; /* Bytes to drop from beginning of packets (for non-compliant devices) */ unsigned int running: 1; /* running status */ |