Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752874AbaFDXVw (ORCPT ); Wed, 4 Jun 2014 19:21:52 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:39961 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752842AbaFDXVt (ORCPT ); Wed, 4 Jun 2014 19:21:49 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Clemens Ladisch , Takashi Iwai Subject: [PATCH 3.14 094/228] ALSA: usb-audio: work around corrupted TEAC UD-H01 feedback data Date: Wed, 4 Jun 2014 16:22:03 -0700 Message-Id: <20140604232351.071498095@linuxfoundation.org> X-Mailer: git-send-email 1.9.0 In-Reply-To: <20140604232347.966798903@linuxfoundation.org> References: <20140604232347.966798903@linuxfoundation.org> User-Agent: quilt/0.63-1 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Clemens Ladisch 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 [mick37@gmx.de: use sender->udh01_fb_quirk rather than ep->udh01_fb_quirk in snd_usb_handle_sync_urb()] Reported-and-tested-by: Mick Reported-and-tested-by: Andrea Messa Signed-off-by: Takashi Iwai Signed-off-by: Greg Kroah-Hartman --- 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 @@ -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; --- a/sound/usb/endpoint.c +++ b/sound/usb/endpoint.c @@ -469,6 +469,10 @@ 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); @@ -1099,7 +1103,16 @@ 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 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/