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=-7.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 74EA9ECDE4B for ; Thu, 8 Nov 2018 22:12:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 322E92089F for ; Thu, 8 Nov 2018 22:12:06 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="a849wG+C" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 322E92089F Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731618AbeKIHtg (ORCPT ); Fri, 9 Nov 2018 02:49:36 -0500 Received: from mail.kernel.org ([198.145.29.99]:41338 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730588AbeKIHrh (ORCPT ); Fri, 9 Nov 2018 02:47:37 -0500 Received: from localhost (unknown [208.72.13.198]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id C6224208A3; Thu, 8 Nov 2018 22:10:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1541715005; bh=SLLrevI/7BdUx9MQNc+pOxSkoKtNXqUem+N4FoN/vro=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=a849wG+CKZCM1H+mQ9u6XYrARRVOR9BwehPPjSFd+eXfP8mSRaKv2PrINoo+fCUL2 yMghjwhIIp4bCax+9Yr+Kf6+UCn+tOpLGNsdIL0EGxtxV5SluU7Arfv/3yQ47YYtEw Esi5PiLEzwt+5OPf3Oj6qV/fZLESGySmkeA993SU= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Chen-Yu Tsai , Maxime Ripard Subject: [PATCH 4.18 05/34] clk: sunxi-ng: sun4i: Set VCO and PLL bias current to lowest setting Date: Thu, 8 Nov 2018 13:52:34 -0800 Message-Id: <20181108215139.240865556@linuxfoundation.org> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20181108215138.892971755@linuxfoundation.org> References: <20181108215138.892971755@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Chen-Yu Tsai commit 80a6ec7d5e1653208eb53f6738620dab98f6f50e upstream. The default mid-level PLL bias current setting interferes with sigma delta modulation. This manifests as decreased audio quality at lower sampling rates, which sounds like radio broadcast quality, and distortion noises at sampling rates at 48 kHz or above. Changing the bias current settings to the lowest gets rid of the noise. Fixes: de3448519194 ("clk: sunxi-ng: sun4i: Use sigma-delta modulation for audio PLL") Cc: # 4.15.x Signed-off-by: Chen-Yu Tsai Signed-off-by: Maxime Ripard Signed-off-by: Greg Kroah-Hartman --- drivers/clk/sunxi-ng/ccu-sun4i-a10.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) --- a/drivers/clk/sunxi-ng/ccu-sun4i-a10.c +++ b/drivers/clk/sunxi-ng/ccu-sun4i-a10.c @@ -1434,8 +1434,16 @@ static void __init sun4i_ccu_init(struct return; } - /* Force the PLL-Audio-1x divider to 1 */ val = readl(reg + SUN4I_PLL_AUDIO_REG); + + /* + * Force VCO and PLL bias current to lowest setting. Higher + * settings interfere with sigma-delta modulation and result + * in audible noise and distortions when using SPDIF or I2S. + */ + val &= ~GENMASK(25, 16); + + /* Force the PLL-Audio-1x divider to 1 */ val &= ~GENMASK(29, 26); writel(val | (1 << 26), reg + SUN4I_PLL_AUDIO_REG);