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[2620:137:e000::1:20]) by mx.google.com with ESMTP id t12-20020a170902bc4c00b0018280f67482si16367773plz.113.2022.11.02.21.57.30; Wed, 02 Nov 2022 21:57:43 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@gmail.com header.s=20210112 header.b=jacehTQd; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231124AbiKCEcf (ORCPT + 97 others); Thu, 3 Nov 2022 00:32:35 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55680 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231217AbiKCEcJ (ORCPT ); Thu, 3 Nov 2022 00:32:09 -0400 Received: from mail-oa1-x36.google.com (mail-oa1-x36.google.com [IPv6:2001:4860:4864:20::36]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 182CC1B78A; Wed, 2 Nov 2022 21:30:36 -0700 (PDT) Received: by mail-oa1-x36.google.com with SMTP id 586e51a60fabf-13c569e5ff5so944253fac.6; Wed, 02 Nov 2022 21:30:36 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:sender:from:to:cc:subject:date:message-id :reply-to; bh=beWe+uN+ON3DnKB4aGPZ3xvAANzoMjyW6vf2PFY929c=; b=jacehTQdxGORVtrgfvg0hPn0N5GQ2IUEGiL/11ZLmE5QRgqMbF6clRydJ/bAvwS1O8 8Z9UR6DiWWKEVePi87bU5voHcQV4UUftDtF/6e95DaD5ELfNE8JHWHhWwkraGlHT/ig8 jVeu1W283oM+9PRjGW7YZCKVy6Y+RNb+STI4bXXVQI/4SK3STy0z5ozLwJ7779WSKKvP z84gR7ImXU45qb4g7G4KfA4XepQw63t0iJzOVlrVzotBWrSuaJOIJalsiBwyDhXJ4jTV aSlLd0jNwOjRv85WYRIR5emtjHLsA7hQuNulGRxDWHQkyM41tHOLr/kpaknE0i/eknpt Ok4Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:sender:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=beWe+uN+ON3DnKB4aGPZ3xvAANzoMjyW6vf2PFY929c=; b=bqEmPCVjQrPK3v+sR3q4UHv/hJR2FIk38nBo1gdcbRwhdpaDPMFgLjxJv3gNFYcw56 7pmgJf7t3b8CRkGL3okCmRB7elEDHFL2wcqYh+1D52u0QasMNt5pQJwN/oSvSJM9W9aF RyP7DE3Xjc7tDb64UEwpMpGdEIwb5BEzKGXjTHDlfC0YzFTy8xDyah6ggHjVR6fMoMt6 W5ssvjUP4ZOnQTHf3OLhkpbQ1SwJKsG1QphpgfCnSTcozJiCRHMag+oFW12yndHAEZBd emdpXs/xHwdisNeC7kp+h14RAi1JIWjQ+V4ZYKeh6bfia9F8qfJyvi1pQN2GLTxYYrDj 6bag== X-Gm-Message-State: ACrzQf1h1CZjIDXpv/HmDSf+X9v3vTMyXeAriAipf6wrS0ExNl5C3rNK 48qpivtizkrfRM6cjcVKMXbtI0FnxPY= X-Received: by 2002:a05:6870:2487:b0:131:4fee:aec2 with SMTP id s7-20020a056870248700b001314feeaec2mr26066038oaq.69.1667449835919; Wed, 02 Nov 2022 21:30:35 -0700 (PDT) Received: from server.roeck-us.net ([2600:1700:e321:62f0:329c:23ff:fee3:9d7c]) by smtp.gmail.com with ESMTPSA id i3-20020a4addc3000000b0049201e2b8f4sm5150583oov.4.2022.11.02.21.30.35 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 02 Nov 2022 21:30:35 -0700 (PDT) Sender: Guenter Roeck Date: Wed, 2 Nov 2022 21:30:34 -0700 From: Guenter Roeck To: Billy Tsai Cc: "jdelvare@suse.com" , "robh+dt@kernel.org" , "joel@jms.id.au" , "andrew@aj.id.au" , "lee.jones@linaro.org" , "thierry.reding@gmail.com" , "u.kleine-koenig@pengutronix.de" , "p.zabel@pengutronix.de" , "linux-hwmon@vger.kernel.org" , "devicetree@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "linux-aspeed@lists.ozlabs.org" , "linux-kernel@vger.kernel.org" , "linux-pwm@vger.kernel.org" , BMC-SW , "garnermic@meta.com" Subject: Re: [v2 3/3] hwmon: Add Aspeed ast2600 TACH support Message-ID: <20221103043034.GA2113834@roeck-us.net> References: <20221101095156.30591-1-billy_tsai@aspeedtech.com> <20221101095156.30591-4-billy_tsai@aspeedtech.com> <20221101131456.GA1310110@roeck-us.net> <271C521D-8F20-4C86-B3DA-9C0AD74242D4@aspeedtech.com> <20221102170138.GA2913353@roeck-us.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Spam-Status: No, score=-1.5 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_EF,FREEMAIL_ENVFROM_END_DIGIT, FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM,HEADER_FROM_DIFFERENT_DOMAINS, RCVD_IN_DNSWL_NONE,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Nov 03, 2022 at 03:52:59AM +0000, Billy Tsai wrote: > > Can't I use a min/max RPM to let the driver know a reasonable timeout/polling period when > the driver is trying to get RPM? > Beacause that our tach controller have the falg to indicates the hardware detected the change > in the input signal. I need the proper timout to rule out slow RPMs. > If the chip measures the fan speed continuously, why would that ever be a problem, and why wait in the first place instead of just taking the most recent result ? Pretty much every other driver is doing that, so I really don't understand why that would not work here. Guenter