At Thu, 1 May 2014 12:20:22 +0200,
Daniel Mack wrote:
>
> From: Clemens Ladisch <clemens@xxxxxxxxxx>
>
> 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@xxxxxxxxxx>
> [mick37@xxxxxx: use sender->udh01_fb_quirk rather than
> ep->udh01_fb_quirk in snd_usb_handle_sync_urb()]
> Reported-and-tested-by: Mick <mick37@xxxxxx>
> Reported-and-tested-by: Andrea Messa <andr.messa@xxxxxxxxxx>
> Cc: <stable@xxxxxxxxxxxxxxx>
> ---
> 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
>
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