From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755005AbZG1XDv (ORCPT ); Tue, 28 Jul 2009 19:03:51 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754893AbZG1XDs (ORCPT ); Tue, 28 Jul 2009 19:03:48 -0400 Received: from kroah.org ([198.145.64.141]:42914 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754208AbZG1XDq (ORCPT ); Tue, 28 Jul 2009 19:03:46 -0400 X-Mailbox-Line: From gregkh@mini.kroah.org Tue Jul 28 15:59:41 2009 Message-Id: <20090728225941.579958466@mini.kroah.org> User-Agent: quilt/0.48-1 Date: Tue, 28 Jul 2009 15:58:32 -0700 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: stable-review@kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Clemens Ladisch , Takashi Iwai Subject: [patch 04/37] sound: usb-audio: add workaround for Blue Microphones devices References: <20090728225828.431071451@mini.kroah.org> Content-Disposition: inline; filename=sound-usb-audio-add-workaround-for-blue-microphones-devices.patch In-Reply-To: <20090728230145.GA10486@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2.6.27-stable review patch. If anyone has any objections, please let us know. ------------------ From: Clemens Ladisch commit 8886f33f25083a47d5fa24ad7b57bb708c5c5403 upstream. Blue Microphones USB devices have an alternate setting that sends two channels of data to the computer. Unfortunately, the descriptors of that altsetting have a wrong channel setting, which means that any recorded data from such a device has twice the sample rate from what would be expected. This patch adds a workaround to ignore that altsetting. Since these devices have only one actual channel, no data is lost. Signed-off-by: Clemens Ladisch Signed-off-by: Takashi Iwai Signed-off-by: Greg Kroah-Hartman --- sound/usb/usbaudio.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) --- a/sound/usb/usbaudio.c +++ b/sound/usb/usbaudio.c @@ -2674,7 +2674,7 @@ static int parse_audio_endpoints(struct struct usb_interface_descriptor *altsd; int i, altno, err, stream; int format; - struct audioformat *fp; + struct audioformat *fp = NULL; unsigned char *fmt, *csep; int num; @@ -2747,6 +2747,18 @@ static int parse_audio_endpoints(struct continue; } + /* + * Blue Microphones workaround: The last altsetting is identical + * with the previous one, except for a larger packet size, but + * is actually a mislabeled two-channel setting; ignore it. + */ + if (fmt[4] == 1 && fmt[5] == 2 && altno == 2 && num == 3 && + fp && fp->altsetting == 1 && fp->channels == 1 && + fp->format == SNDRV_PCM_FORMAT_S16_LE && + le16_to_cpu(get_endpoint(alts, 0)->wMaxPacketSize) == + fp->maxpacksize * 2) + continue; + csep = snd_usb_find_desc(alts->endpoint[0].extra, alts->endpoint[0].extralen, NULL, USB_DT_CS_ENDPOINT); /* Creamware Noah has this descriptor after the 2nd endpoint */ if (!csep && altsd->bNumEndpoints >= 2)