[ 3.8.y.z extended stable ] Patch "ALSA: snd-usb-usx2y: remove bogus frame checks" has been added to staging queue

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

    ALSA: snd-usb-usx2y: remove bogus frame checks

to the linux-3.8.y-queue branch of the 3.8.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.8.y-queue

This patch is scheduled to be released in version 3.8.13.12.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.8.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From 45395f7e8710c9e376292e804f8fe69f7ef8d3e0 Mon Sep 17 00:00:00 2001
From: Daniel Mack <zonque at gmail.com>
Date: Wed, 2 Oct 2013 17:49:50 +0200
Subject: ALSA: snd-usb-usx2y: remove bogus frame checks

commit a9d14bc0b188a822e42787d01e56c06fe9750162 upstream.

The frame check in i_usX2Y_urb_complete() and
i_usX2Y_usbpcm_urb_complete() is bogus and produces false positives as
described in this LAU thread:

  http://linuxaudio.org/mailarchive/lau/2013/5/20/200177

This patch removes the check code entirely.

Cc: fzu at wemgehoertderstaat.de
Reported-by: Dr Nicholas J Bailey <nicholas.bailey at glasgow.ac.uk>
Suggested-by: Takashi Iwai <tiwai at suse.de>
Signed-off-by: Daniel Mack <zonque at gmail.com>
Signed-off-by: Takashi Iwai <tiwai at suse.de>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 sound/usb/usx2y/usbusx2yaudio.c | 22 +++-------------------
 sound/usb/usx2y/usx2yhwdeppcm.c |  7 +------
 2 files changed, 4 insertions(+), 25 deletions(-)

diff --git a/sound/usb/usx2y/usbusx2yaudio.c b/sound/usb/usx2y/usbusx2yaudio.c
index 0ce90337..cd69a80 100644
--- a/sound/usb/usx2y/usbusx2yaudio.c
+++ b/sound/usb/usx2y/usbusx2yaudio.c
@@ -299,19 +299,6 @@ static void usX2Y_error_urb_status(struct usX2Ydev *usX2Y,
 	usX2Y_clients_stop(usX2Y);
 }

-static void usX2Y_error_sequence(struct usX2Ydev *usX2Y,
-				 struct snd_usX2Y_substream *subs, struct urb *urb)
-{
-	snd_printk(KERN_ERR
-"Sequence Error!(hcd_frame=%i ep=%i%s;wait=%i,frame=%i).\n"
-"Most probably some urb of usb-frame %i is still missing.\n"
-"Cause could be too long delays in usb-hcd interrupt handling.\n",
-		   usb_get_current_frame_number(usX2Y->dev),
-		   subs->endpoint, usb_pipein(urb->pipe) ? "in" : "out",
-		   usX2Y->wait_iso_frame, urb->start_frame, usX2Y->wait_iso_frame);
-	usX2Y_clients_stop(usX2Y);
-}
-
 static void i_usX2Y_urb_complete(struct urb *urb)
 {
 	struct snd_usX2Y_substream *subs = urb->context;
@@ -328,12 +315,9 @@ static void i_usX2Y_urb_complete(struct urb *urb)
 		usX2Y_error_urb_status(usX2Y, subs, urb);
 		return;
 	}
-	if (likely((urb->start_frame & 0xFFFF) == (usX2Y->wait_iso_frame & 0xFFFF)))
-		subs->completed_urb = urb;
-	else {
-		usX2Y_error_sequence(usX2Y, subs, urb);
-		return;
-	}
+
+	subs->completed_urb = urb;
+
 	{
 		struct snd_usX2Y_substream *capsubs = usX2Y->subs[SNDRV_PCM_STREAM_CAPTURE],
 			*playbacksubs = usX2Y->subs[SNDRV_PCM_STREAM_PLAYBACK];
diff --git a/sound/usb/usx2y/usx2yhwdeppcm.c b/sound/usb/usx2y/usx2yhwdeppcm.c
index f2a1acd..814d0e8 100644
--- a/sound/usb/usx2y/usx2yhwdeppcm.c
+++ b/sound/usb/usx2y/usx2yhwdeppcm.c
@@ -244,13 +244,8 @@ static void i_usX2Y_usbpcm_urb_complete(struct urb *urb)
 		usX2Y_error_urb_status(usX2Y, subs, urb);
 		return;
 	}
-	if (likely((urb->start_frame & 0xFFFF) == (usX2Y->wait_iso_frame & 0xFFFF)))
-		subs->completed_urb = urb;
-	else {
-		usX2Y_error_sequence(usX2Y, subs, urb);
-		return;
-	}

+	subs->completed_urb = urb;
 	capsubs = usX2Y->subs[SNDRV_PCM_STREAM_CAPTURE];
 	capsubs2 = usX2Y->subs[SNDRV_PCM_STREAM_CAPTURE + 2];
 	playbacksubs = usX2Y->subs[SNDRV_PCM_STREAM_PLAYBACK];
--
1.8.1.2