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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 662FDC61DA4 for ; Thu, 16 Feb 2023 10:18:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229845AbjBPKSZ (ORCPT ); Thu, 16 Feb 2023 05:18:25 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55116 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229538AbjBPKSW (ORCPT ); Thu, 16 Feb 2023 05:18:22 -0500 Received: from mail-ej1-x629.google.com (mail-ej1-x629.google.com [IPv6:2a00:1450:4864:20::629]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B9EEA2100 for ; Thu, 16 Feb 2023 02:18:21 -0800 (PST) Received: by mail-ej1-x629.google.com with SMTP id f21so3907107ejq.8 for ; Thu, 16 Feb 2023 02:18:21 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=content-transfer-encoding:in-reply-to:from:references:cc:to :content-language:subject:user-agent:mime-version:date:message-id :from:to:cc:subject:date:message-id:reply-to; bh=7xRm+/4FpVvgULsREaJ7c5e2nJTQURFW8fIUCxaU0fg=; b=TmElzeXhZ8MfrNoiINxw/tdWJq2JGa6TL8u+fpv007IvJnZRydkm2lddBKE1nx2BJJ Rfv6dGu43MeuPWiqvwnEh5bxb7+qjyc/LzEX5x1vlgxKJF3OdhBEwql+A+97nHFA0Xa4 IvUmUVjQostyxhOlmOZzCEeqa5ffZOfSuaj69rc5UgAYg+4/XpRFek4EnZKBBOZn871u vwzWNyQ8O3IZDGCt4XDzFwktjB46cBdlc3a7ipg9KSBXplNap+g0l6jyltHtPU9ieZe6 Xx8KX7HD25nSAQT8aAwjNm3bT42KF9/yH/9VsVTwqQ5QPFXssZs3867EYV2HGO4kQSeV AWLA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:in-reply-to:from:references:cc:to :content-language:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=7xRm+/4FpVvgULsREaJ7c5e2nJTQURFW8fIUCxaU0fg=; b=NImoI62x7vq4/+New7B8zdNLa+tc44zt5lOgz+Llak7Aqaap9ngeWKZvdfNpyio4fZ Vrk7Lwb+OBf9UfiAvud7XM9l9I0/mOm3yiKKQljrqaGo7VZ9/in8HChsz1wA2XL/MeBq yeaNXTA3UTwBQi7NLzK4cJseUWAj27eYXYV3MRSbcytOok9TuHgG9EhHhtSAsp2dzNEo HT1xgRelhtRL/7X4m/Jp+M8LStnXzfgCessDtTnGZb+ENCZWS+XUoj9Qj4drq4mQ9EDO Du+JFfP9FLQ+JscwmCiyv4iAhO6OXjbaisIjKZRxf0T1u5DFA92poYWI09n4gmlhLqfh 9Ftw== X-Gm-Message-State: AO0yUKWtC/bk8n8SgzIUOmRVfIhA7rbdF+Em3DrWn9oudkWSGzaC1skr FWmylskX9fwrdCGmI61M0UUtIg== X-Google-Smtp-Source: AK7set+DarsZaH/hWMGy/10viYDOBB2pRRqKtjz34oEaeF2il4rj0qe7sZICD8Ug1ebcxd/f0RjKUQ== X-Received: by 2002:a17:906:3e56:b0:878:7f6e:38a7 with SMTP id t22-20020a1709063e5600b008787f6e38a7mr7620274eji.44.1676542700243; Thu, 16 Feb 2023 02:18:20 -0800 (PST) Received: from [192.168.1.109] ([178.197.216.144]) by smtp.gmail.com with ESMTPSA id x17-20020a1709064a9100b008b12614ee06sm610840eju.161.2023.02.16.02.18.18 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 16 Feb 2023 02:18:19 -0800 (PST) Message-ID: Date: Thu, 16 Feb 2023 11:18:16 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.7.1 Subject: Re: [PATCH 2/3] ASoC: dt-bindings: sama7g5-pdmc: add microchip,startup-delay-us binding Content-Language: en-US To: Claudiu.Beznea@microchip.com, lgirdwood@gmail.com, broonie@kernel.org, robh+dt@kernel.org, krzysztof.kozlowski+dt@linaro.org, lars@metafoo.de, perex@perex.cz, tiwai@suse.com, Nicolas.Ferre@microchip.com, alexandre.belloni@bootlin.com Cc: alsa-devel@alsa-project.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org References: <20230214161435.1088246-1-claudiu.beznea@microchip.com> <20230214161435.1088246-3-claudiu.beznea@microchip.com> <485d74fe-bfb5-c55e-724f-304476624abd@linaro.org> <954cdf90-c41a-4e21-31e0-88a0baf26065@microchip.com> From: Krzysztof Kozlowski In-Reply-To: <954cdf90-c41a-4e21-31e0-88a0baf26065@microchip.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 16/02/2023 11:15, Claudiu.Beznea@microchip.com wrote: > On 16.02.2023 12:04, Krzysztof Kozlowski wrote: >> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe >> >> On 14/02/2023 17:14, Claudiu Beznea wrote: >>> Add microchip,startup-delay-us binding to let PDMC users to specify >>> startup delay. >>> >>> Signed-off-by: Claudiu Beznea >>> --- >>> .../devicetree/bindings/sound/microchip,sama7g5-pdmc.yaml | 6 ++++++ >>> 1 file changed, 6 insertions(+) >>> >>> diff --git a/Documentation/devicetree/bindings/sound/microchip,sama7g5-pdmc.yaml b/Documentation/devicetree/bindings/sound/microchip,sama7g5-pdmc.yaml >>> index c4cf1e5ab84b..9b40268537cb 100644 >>> --- a/Documentation/devicetree/bindings/sound/microchip,sama7g5-pdmc.yaml >>> +++ b/Documentation/devicetree/bindings/sound/microchip,sama7g5-pdmc.yaml >>> @@ -67,6 +67,12 @@ properties: >>> maxItems: 4 >>> uniqueItems: true >>> >>> + microchip,startup-delay-us: >>> + description: | >>> + Specifies the delay in microseconds that needs to be applied after >>> + enabling the PDMC microphones to avoid unwanted noise due to microphones >>> + not being ready. >> >> Is this some hardware delay? Or OS? If OS, why Linux specific delay is >> put into DT? > > It's the delay used in software workaround that IP needs to filter noises. Then this sounds like OS? Linux related properties usually do not belong to DT. > The IP is not fully featured to do this kind of filtering on its own thus > this software workaround. This delay may depend on used microphones thus > for different kind of setups (PDMC + different microphones) I introduced > this in DT. I understand your driver needs delay and I am not questioning this. I am questioning why this is suitable for DT? Best regards, Krzysztof