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=-2.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no 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 983ABC432C0 for ; Tue, 3 Dec 2019 13:57:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 70DEF2073C for ; Tue, 3 Dec 2019 13:57:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1575381454; bh=dMhjP/jievxghATJcetWe9ihqNrI1HEWKB+ljOEzpDo=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=a8moiNxfhEDGRHXBWq4nhhmhS7tyqSUSM6b+LVIMytGa30AiqawNj3Wd1BxKlkSdH i1KOq3qCepX9LWeQsMy7qnLb0mYuORkjbmc+6vN0j6o2pdU+g+5HexNV9jo7NbGhUi wk3VJFN9TPkC0lF7BMmOTvKjG18ZhHCLlXmBOFtE= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727321AbfLCN5d (ORCPT ); Tue, 3 Dec 2019 08:57:33 -0500 Received: from heliosphere.sirena.org.uk ([172.104.155.198]:34166 "EHLO heliosphere.sirena.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726024AbfLCN5b (ORCPT ); Tue, 3 Dec 2019 08:57:31 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sirena.org.uk; s=20170815-heliosphere; h=In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=dMhjP/jievxghATJcetWe9ihqNrI1HEWKB+ljOEzpDo=; b=qCGwg1s5egJ+XIcBGmbCeXgZw GkcvAIc1pnYNLUidCLIQZQ1rkCb3/AaNvfHaw2loeRf8KcobDk6Iffw3GKAPXozE/QTADJ6YLeO3E LBtKDhQD5iQ8Yb9teK9l63w1MuTBjRWc/IJrO/8QUvVY0i8/qsNLLSD9Mkq/rXPg1gbqQ=; Received: from fw-tnat-cam1.arm.com ([217.140.106.49] helo=fitzroy.sirena.org.uk) by heliosphere.sirena.org.uk with esmtpsa (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1ic8g2-0002b9-0S; Tue, 03 Dec 2019 13:57:18 +0000 Received: by fitzroy.sirena.org.uk (Postfix, from userid 1000) id 916A0D002FA; Tue, 3 Dec 2019 13:57:17 +0000 (GMT) Date: Tue, 3 Dec 2019 13:57:17 +0000 From: Mark Brown To: Brent Lu Cc: alsa-devel@alsa-project.org, Support Opensource , Liam Girdwood , Jaroslav Kysela , Takashi Iwai , linux-kernel@vger.kernel.org Subject: Re: [PATCH] ASoC: da7219: remove SRM lock check retry Message-ID: <20191203135717.GH1998@sirena.org.uk> References: <1575358265-17905-1-git-send-email-brent.lu@intel.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="jRdC2OsRnuV8iIl8" Content-Disposition: inline In-Reply-To: <1575358265-17905-1-git-send-email-brent.lu@intel.com> X-Cookie: Cleanliness is next to impossible. User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --jRdC2OsRnuV8iIl8 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Tue, Dec 03, 2019 at 03:31:05PM +0800, Brent Lu wrote: > For platforms not able to provide WCLK in the PREPARED runtime state, it > takes 400ms for codec driver to print the message "SRM failed to lock" in > the da7219_dai_event() function which is called when DAPM widgets are > powering up. The latency penalty to audio input/output is too much so the > retry (8 times) and delay (50ms each retry) are removed. > Another reason is current Cold output latency requirement in Android CDD is > 500ms but will be reduced to 200ms for 2021 platforms. With the 400ms > latency it would be difficult to pass the Android CTS test. Adam pointed out some specific problems this causes here but at a higher level this commit message isn't great since it just says "I don't like these delays so I made them shorter" which doesn't really explain what the delays are doing or why it's OK to make them shorter - there are plenty of audio devices which require longer ramp times than people would like out there but there's usually good solid reasons why the delays have to be there. --jRdC2OsRnuV8iIl8 Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAABCgAdFiEEreZoqmdXGLWf4p/qJNaLcl1Uh9AFAl3mabYACgkQJNaLcl1U h9Alvgf+O6LAdo281NDSae5rpCvfsxmLKh9POrtFw+1BQ0Sj8NX6kAjrShi6x//G pXpypd9N3ikWjox5Fakw7VK1jz5QWUSdGR2PooLz1l8yJiu8KS13BAzZ128+9wzx xAHMDv4Y4bEAUF6etkVz+C4cjjrvpPoJls41Fkd+mgUf4YJoSI1/2vaveJsh3SFZ MqqGaxVSJF6Y8NkCiCi1iuwMJ54NEj0StvAJs/DoaC9QAgCKMJBN3A3mbtDvZrWD efAisKVDhkz+xa6BUV+jW57SnSmFWvTY5zWBLCJGgnCHh2NWURd3nmEuV4kwtDdC Svgjke4iToZwagfrdJkWbA4FqfAuMQ== =jUTM -----END PGP SIGNATURE----- --jRdC2OsRnuV8iIl8--