From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 69CA5C169C4 for ; Sun, 3 Feb 2019 14:27:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 421CA2082C for ; Sun, 3 Feb 2019 14:27:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730616AbfBCO10 (ORCPT ); Sun, 3 Feb 2019 09:27:26 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:55556 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730126AbfBCOUr (ORCPT ); Sun, 3 Feb 2019 09:20:47 -0500 Received: from cable-78.29.236.164.coditel.net ([78.29.236.164] helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1gqIda-0006M5-D2; Sun, 03 Feb 2019 14:20:46 +0000 Received: from ben by deadeye with local (Exim 4.92-RC4) (envelope-from ) id 1gqI9Z-00070d-HD; Sun, 03 Feb 2019 14:49:45 +0100 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, Denis Kirjanov , "Takashi Iwai" , "Alex Stanoev" Date: Sun, 03 Feb 2019 14:45:08 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) X-Patchwork-Hint: ignore Subject: [PATCH 3.16 121/305] ALSA: ca0106: Disable IZD on SB0570 DAC to fix audio pops In-Reply-To: X-SA-Exim-Connect-IP: 78.29.236.164 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.63-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Alex Stanoev commit ac237c28d5ac1b241d58b1b7b4b9fa10efb22fb5 upstream. The Creative Audigy SE (SB0570) card currently exhibits an audible pop whenever playback is stopped or resumed, or during silent periods of an audio stream. Initialise the IZD bit to the 0 to eliminate these pops. The Infinite Zero Detection (IZD) feature on the DAC causes the output to be shunted to Vcap after 2048 samples of silence. This discharges the AC coupling capacitor through the output and causes the aforementioned pop/click noise. The behaviour of the IZD bit is described on page 15 of the WM8768GEDS datasheet: "With IZD=1, applying MUTE for 1024 consecutive input samples will cause all outputs to be connected directly to VCAP. This also happens if 2048 consecutive zero input samples are applied to all 6 channels, and IZD=0. It will be removed as soon as any channel receives a non-zero input". I believe the second sentence might be referring to IZD=1 instead of IZD=0 given the observed behaviour of the card. This change should make the DAC initialisation consistent with Creative's Windows driver, as this popping persists when initialising the card in Linux and soft rebooting into Windows, but is not present on a cold boot to Windows. Signed-off-by: Alex Stanoev Signed-off-by: Takashi Iwai Signed-off-by: Ben Hutchings --- sound/pci/ca0106/ca0106.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/sound/pci/ca0106/ca0106.h +++ b/sound/pci/ca0106/ca0106.h @@ -582,7 +582,7 @@ #define SPI_PL_BIT_R_R (2<<7) /* right channel = right */ #define SPI_PL_BIT_R_C (3<<7) /* right channel = (L+R)/2 */ #define SPI_IZD_REG 2 -#define SPI_IZD_BIT (1<<4) /* infinite zero detect */ +#define SPI_IZD_BIT (0<<4) /* infinite zero detect */ #define SPI_FMT_REG 3 #define SPI_FMT_BIT_RJ (0<<0) /* right justified mode */