Discussion:
[PATCH v2] ALSA: usb-audio: work around corrupted TEAC UD-H01 feedback data
(too old to reply)
Daniel Mack
2014-05-01 10:20:22 UTC
Permalink
From: Clemens Ladisch <***@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 <***@ladisch.de>
[***@gmx.de: use sender->udh01_fb_quirk rather than
ep->udh01_fb_quirk in snd_usb_handle_sync_urb()]
Reported-and-tested-by: Mick <***@gmx.de>
Reported-and-tested-by: Andrea Messa <***@tiscali.it>
Cc: <***@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,
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
Takashi Iwai
2014-05-02 16:23:27 UTC
Permalink
At Thu, 1 May 2014 12:20:22 +0200,
Post by Daniel Mack
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.
ep->udh01_fb_quirk in snd_usb_handle_sync_urb()]
---
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
Post by Daniel Mack
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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