ALSA: usb-audio: work around corrupted TEAC UD-H01 feedback data

The TEAC UD-H01 firmware sends wrong feedback frequency values, thus
causing the PC to send the samples at a wrong rate, which results in
clicks and crackles in the output.

Add a workaround to detect and fix the corruption.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
[mick37@gmx.de: use sender->udh01_fb_quirk rather than
 ep->udh01_fb_quirk in snd_usb_handle_sync_urb()]
Reported-and-tested-by: Mick <mick37@gmx.de>
Reported-and-tested-by: Andrea Messa <andr.messa@tiscali.it>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

1 files changed, 1 insertions, 0 deletions

diff --git a/sound/usb/card.h b/sound/usb/card.h
index 9867ab866857..97acb906acc2 100644
--- a/sound/usb/card.h
+++ b/sound/usb/card.h
@@ -92,6 +92,7 @@ struct snd_usb_endpoint {
         unsigned int curframesize;      /* current packet size in frames (for capture) */
         unsigned int syncmaxsize;       /* sync endpoint packet size */
         unsigned int fill_max:1;        /* fill max packet size always */
+        unsigned int udh01_fb_quirk:1;  /* corrupted feedback data */
         unsigned int datainterval;      /* log_2 of data packet interval */
         unsigned int syncinterval;      /* P for adaptive mode, 0 otherwise */
         unsigned char silence_value;