This is a note to let you know that I've just added the patch titled
ALSA: usb-audio: work around corrupted TEAC UD-H01 feedback data
to the 3.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
alsa-usb-audio-work-around-corrupted-teac-ud-h01-feedback-data.patch
and it can be found in the queue-3.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.
>From 7040b6d1febfdbd9c1595efb751d492cd2503f96 Mon Sep 17 00:00:00 2001
From: Clemens Ladisch <[email protected]>
Date: Thu, 1 May 2014 12:20:22 +0200
Subject: ALSA: usb-audio: work around corrupted TEAC UD-H01 feedback data
From: Clemens Ladisch <[email protected]>
commit 7040b6d1febfdbd9c1595efb751d492cd2503f96 upstream.
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 <[email protected]>
[[email protected]: use sender->udh01_fb_quirk rather than
ep->udh01_fb_quirk in snd_usb_handle_sync_urb()]
Reported-and-tested-by: Mick <[email protected]>
Reported-and-tested-by: Andrea Messa <[email protected]>
Signed-off-by: Takashi Iwai <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
sound/usb/card.h | 1 +
sound/usb/endpoint.c | 15 ++++++++++++++-
2 files changed, 15 insertions(+), 1 deletion(-)
--- a/sound/usb/card.h
+++ b/sound/usb/card.h
@@ -90,6 +90,7 @@ 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;
--- a/sound/usb/endpoint.c
+++ b/sound/usb/endpoint.c
@@ -467,6 +467,10 @@ struct snd_usb_endpoint *snd_usb_add_end
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);
@@ -1075,7 +1079,16 @@ void snd_usb_handle_sync_urb(struct snd_
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
Patches currently in stable-queue which might be from [email protected] are
queue-3.10/alsa-usb-audio-work-around-corrupted-teac-ud-h01-feedback-data.patch
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