Received: by 2002:ac0:aed5:0:0:0:0:0 with SMTP id t21csp6062079imb; Fri, 8 Mar 2019 08:27:56 -0800 (PST) X-Google-Smtp-Source: APXvYqzeVWMqVktFZvLsnFPZFMwKThp7BBkz+uQnAWsgnnXfnrL7YT9MAv1z1OWFmNOadhfFYOXb X-Received: by 2002:a63:c242:: with SMTP id l2mr12053887pgg.138.1552062476047; Fri, 08 Mar 2019 08:27:56 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1552062476; cv=none; d=google.com; s=arc-20160816; b=nFPehFAV8cF2tcuI3qlE0th0ju8lbcMLqtCD3CbKn7QIsZH2Pl4knci2mibWLib8un fErarGx5a1H6A8J95LfQGDy0SNmUeGNlT060u3VbeyQeNpMdZwLYNgCSTp/GQvIHfWHl cjaXtF9jG6G1M3+xa9rMpfel2aViMeWpsO8oi2ctElS5Jd4N2MXIaOU3iVpPm/y7Tpgx ZA6EdCDe37baBJzUsrIMKGU/SH5X1JVlZQygpM6MxsULhRSO+W7F+bgngFiu4E31sfca Cd1tiP082DCXOg4zj1wndTfr2ELQptvskKRJrwvSIgPMVYGBDLctj4EtwXcaUhf5Wilf 4vYw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:dkim-signature; bh=wDfjrwg75YR9Z83PlwiJKxEdJg7htxsYg+OzHK9l1UA=; b=gL/Hkqbxi460kBOnquz1uQpF6paGsvRQAuJA18euxVjgMCelUpLxJcJ8IdmTU7kgXe 5TjP8+x8LO8TpkHfyPKDtln5ywbW8KnVN0Qz0A0KHoUZlRl3lDoNDQGhSg3ZrPxcz71u 3wCopUPAxvLaQSUx2e1Y4VB7Osd+xFKnOe4KDl00i8VtdNxBJaSp0DgX9Ps9cZcaVctM uYcSQlc8P/oh5mzg5v9y/4eQclIaNDwaH7uVI++U7WeMtRPQf50dERzgN5SsHI1s0ok4 5y58gdVUKsY+XvDcV0tZV+6JM8zJ2wIeC19rqLdunS6Z+VAw2y0wrod/YZJrg93QEvCs EAew== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@gmail.com header.s=20161025 header.b=JSl510lZ; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=QUARANTINE dis=NONE) header.from=gmail.com Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id b1si6737714pgq.72.2019.03.08.08.27.39; Fri, 08 Mar 2019 08:27:56 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=pass header.i=@gmail.com header.s=20161025 header.b=JSl510lZ; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=QUARANTINE dis=NONE) header.from=gmail.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726357AbfCHQ1U (ORCPT + 99 others); Fri, 8 Mar 2019 11:27:20 -0500 Received: from mail-ed1-f67.google.com ([209.85.208.67]:41585 "EHLO mail-ed1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726171AbfCHQ1U (ORCPT ); Fri, 8 Mar 2019 11:27:20 -0500 Received: by mail-ed1-f67.google.com with SMTP id x7so16863914eds.8 for ; Fri, 08 Mar 2019 08:27:19 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=wDfjrwg75YR9Z83PlwiJKxEdJg7htxsYg+OzHK9l1UA=; b=JSl510lZaTZdoWEZeKs13cdg+xWLOUiNXtcro1BCnvTN9fM7lElEKk5D0ps5FsLUFe 5rMhjVq1G7tVo9LbURDZya+Rz4h49M80QxYq6ZVav2XAHmoO6PXs+Zzgwt40v3HcieBf d63gi/fmDWdlRf7Q4NIv/QmWUMjIsT8KlYIVSwMdOEe67io8kdiWJ10lT10R2eQdVs/M /cIbv6Ma7yN4W1henWpBrA9+baQRiDkPFGIuRXfklJRojeWefvXmrURoZ3BhObPLf0rq IMdV5Hcy9KsbqsQefdjmNLjsb7J/P0ElZfxF7YOXS3XoRBO8NQRSgXjdFJLOM3aJ+tJL LWNA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=wDfjrwg75YR9Z83PlwiJKxEdJg7htxsYg+OzHK9l1UA=; b=dNo3tXw8gbnH96QCN+l0YNh+CTKZHjO1FH0kgaOzWRfhx5mZ4vQc+QmRYrfJJzrHkz OKWV9ney/JAAzp1JiI58D0s2IKAxguOsxY/Gd8Qy1eqqxS8UCothyPjOVtr54z7SDwPP WB7lnt6cG/SdnEM61YbaouKTXOFAppRCw33AQAd7lH/Q6uwO2Me9Yf5NEVQCZSbjV5p+ 3givaetRz0wMiKULrbXWPQAMz5Z59WfXYWuZxMZYNZyBlQsGlbsPhAZ67Xau1IaB6Kpn fb9ZkFeQ3L8lwLYOCX3DtKxfGfmnpacNcUTgMQ0GnELxv2tWpDP+tWcp+1IH1f5jjGZj F+qg== X-Gm-Message-State: APjAAAUjPH8PnzPnvExfS7kciPDeDKsnbbJtIZvMLLL9L77IH09eVezl xJu4FcpUrYhbMrJ6PiHnoLc9wTVi0iArkxrMT9c= X-Received: by 2002:a50:d8ce:: with SMTP id y14mr33032341edj.101.1552062438308; Fri, 08 Mar 2019 08:27:18 -0800 (PST) MIME-Version: 1.0 References: <20190308160933.29899-1-daniel.baluta@nxp.com> In-Reply-To: From: Daniel Baluta Date: Fri, 8 Mar 2019 18:27:06 +0200 Message-ID: Subject: Re: [PATCH] ASoC: fsl: sai: Reduce underrun when stream starts To: Fabio Estevam Cc: Daniel Baluta , "broonie@kernel.org" , "tiwai@suse.com" , "alsa-devel@alsa-project.org" , "linux-kernel@vger.kernel.org" , "Xiubo.Lee@gmail.com" , "nicoleotsuka@gmail.com" , dl-linux-imx , "S.j. Wang" Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Mar 8, 2019 at 6:16 PM Fabio Estevam wrote: > > Hi Daniel, > > On Fri, Mar 8, 2019 at 1:09 PM Daniel Baluta wrote: > > > > From: Shengjiu Wang > > > > Write initial words into SAI FIFO to reduce the underrun > > error. > > Please provide a better explanation. Hi Fabio, Fair enough, will try to provide a better description in v2 that will also address your questions below. > > Why does performing these writes help? > > Also, the commit message says "reduce", so it seems this is a > workaround instead of a proper fix?