At Thu, 1 May 2014 12:20:22 +0200, Daniel Mack wrote:

From: Clemens Ladisch clemens@ladisch.de

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

---

Clemens, I hope you're ok that I resend this patch. With Mick's minor amendment (use sender->udh01_fb_quirk rather than ep->udh01_fb_quirk), Andrea Messa also reported success with the same hardware model.

Thanks, applied now. Let me know if this gives any problems.

Takashi

Thanks, Daniel

sound/usb/card.h | 1 + sound/usb/endpoint.c | 15 ++++++++++++++- 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/sound/usb/card.h b/sound/usb/card.h index 9867ab8..97acb90 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;

diff --git a/sound/usb/endpoint.c b/sound/usb/endpoint.c index e70a87e..289f582 100644 --- a/sound/usb/endpoint.c +++ b/sound/usb/endpoint.c @@ -471,6 +471,10 @@ struct snd_usb_endpoint *snd_usb_add_endpoint(struct snd_usb_audio *chip, ep->syncinterval = 3;

ep->syncmaxsize = le16_to_cpu(get_endpoint(alts, 1)->wMaxPacketSize);

• if (chip->usb_id == USB_ID(0x0644, 0x8038) /* TEAC UD-H01 */ &&
  

•     ep->syncmaxsize == 4)
  

• 	ep->udh01_fb_quirk = 1;
  

  }

  list_add_tail(&ep->list, &chip->ep_list);

@@ -1105,7 +1109,16 @@ void snd_usb_handle_sync_urb(struct snd_usb_endpoint *ep, if (f == 0) return;

• if (unlikely(ep->freqshift == INT_MIN)) {

• if (unlikely(sender->udh01_fb_quirk)) {

• /*
  

•  * The TEAC UD-H01 firmware sometimes changes the feedback value
  

•  * by +/- 0x1.0000.
  

•  */
  

• if (f < ep->freqn - 0x8000)
  

• 	f += 0x10000;
  

• else if (f > ep->freqn + 0x8000)
  

• 	f -= 0x10000;
  

• } else if (unlikely(ep->freqshift == INT_MIN)) { /*
  • The first time we see a feedback value, determine its format
  • by shifting it left or right until it matches the nominal

-- 1.9.0