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 B942EC433F5 for ; Mon, 31 Jan 2022 20:10:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1343693AbiAaUKS (ORCPT ); Mon, 31 Jan 2022 15:10:18 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59280 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229534AbiAaUKP (ORCPT ); Mon, 31 Jan 2022 15:10:15 -0500 Received: from mail-oi1-x22b.google.com (mail-oi1-x22b.google.com [IPv6:2607:f8b0:4864:20::22b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8CC2FC061714; Mon, 31 Jan 2022 12:10:15 -0800 (PST) Received: by mail-oi1-x22b.google.com with SMTP id q8so14439538oiw.7; Mon, 31 Jan 2022 12:10:15 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=sender:message-id:date:mime-version:user-agent:subject :content-language:to:cc:references:from:in-reply-to :content-transfer-encoding; bh=md82yNcHzb9hUMdO0D3wtsJDnKHtblS8Ove1AcpVwL4=; b=oXTOBWrpW2gl4tIhPPYXSYCdP3/cyVxxxJjLIU/H6PIvlisO2smazTA843hl8ym1lu UQ7nFj5dP4YilaIX47t5/UUo3/rF1VOovK3M3N2EaKiJGlRHmJX3+FjlpirLm3l1VzQJ rTInEmWelM97XSI0pjbfRPDkUZWpKI/Dx/4W61B0pNtP215V96YLYxf9HE8o5Kuboq3Z NIit3Xta78XA6PRj0xsV3mDcMaibY61xh8H5qnodjaHfE+ADK0mi2swPIdYKxgmuVmXr yMBQfMmLflXEcCe0vR8b9sX+XFzGMouCZTpVbj0PuFA78c5fM8NvMXqdOtzsD4X4snjM EA7Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:sender:message-id:date:mime-version:user-agent :subject:content-language:to:cc:references:from:in-reply-to :content-transfer-encoding; bh=md82yNcHzb9hUMdO0D3wtsJDnKHtblS8Ove1AcpVwL4=; b=cMFAB+MOAzCT6M1T3tWMF6FduCB+S5wbtnRvUWBY/KID8MS6abpH4V0xP1DraTPsL9 xENOacZXbdo3xRUSM9Q+6+S/ncOZVvqC4+cKcVRXAzEbNNCHRSfgTgjJETiNuIz8p5+m 8NAUCV0lIIlX5TxhPtMFOR31EaYik0PzZW2hHr+IrANvfm3Fm+vPbePo/IFrrHXOWmYB AtgyHhvJkF6HDxhSgdCgKpTsec79PPsv+xCMQWaH2h9q1wAzAw6FCjMZli3VjLJnOllR oA2xs4lC535jMWg78vwBGRIMDfZOJfhX7lwAkHqSlbuEv9T4bJcrk0j2z2jyr13b9n6V S2YQ== X-Gm-Message-State: AOAM533nCrcqHOoJbyWAHsai8wFTlMSF7RA2HZU7TDit3IAv2kJ9a82v jJvSrih4ETqA3YotkPUfuVagiuYp1/pWRQ== X-Google-Smtp-Source: ABdhPJxGKaP8CEQPw0ggAidZHCs0odovFzUCuaCNznTdQv7o1VKhCNXQn2SGRGodc/39NDolZDqXOA== X-Received: by 2002:a05:6808:1443:: with SMTP id x3mr13850490oiv.40.1643659814832; Mon, 31 Jan 2022 12:10:14 -0800 (PST) Received: from ?IPV6:2600:1700:e321:62f0:329c:23ff:fee3:9d7c? ([2600:1700:e321:62f0:329c:23ff:fee3:9d7c]) by smtp.gmail.com with ESMTPSA id t21sm8177727otq.81.2022.01.31.12.10.13 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 31 Jan 2022 12:10:14 -0800 (PST) Sender: Guenter Roeck Message-ID: <3af7602a-1703-4ff2-3905-dfd35742dd90@roeck-us.net> Date: Mon, 31 Jan 2022 12:10:12 -0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.5.0 Subject: Re: [PATCH v2 3/4] hwmon: (sch56xx-common) Replace msleep() with usleep_range() Content-Language: en-US To: Armin Wolf , hdegoede@redhat.com Cc: jdelvare@suse.com, linux-hwmon@vger.kernel.org, linux-kernel@vger.kernel.org References: <20220131193137.3684-1-W_Armin@gmx.de> <20220131193137.3684-4-W_Armin@gmx.de> From: Guenter Roeck In-Reply-To: <20220131193137.3684-4-W_Armin@gmx.de> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 1/31/22 11:31, Armin Wolf wrote: > msleep(1) will often sleep more than 20ms, slowing down sensor > and watchdog reads/writes. Use usleep_range() as recommended > in timers-howto.rst to fix that. > > Tested on a Fujitsu Esprimo P720. > > Signed-off-by: Armin Wolf > --- > drivers/hwmon/sch56xx-common.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/hwmon/sch56xx-common.c b/drivers/hwmon/sch56xx-common.c > index 0172aa16dc0c..f66e1ed4b1aa 100644 > --- a/drivers/hwmon/sch56xx-common.c > +++ b/drivers/hwmon/sch56xx-common.c > @@ -139,7 +139,7 @@ static int sch56xx_send_cmd(u16 addr, u8 cmd, u16 reg, u8 v) > /* EM Interface Polling "Algorithm" */ > for (i = 0; i < max_busy_polls + max_lazy_polls; i++) { > if (i >= max_busy_polls) > - msleep(1); > + usleep_range(1, 2); This replaces a 1-millisecond sleep with a 1-2 microsecond sleep. Are you sure this is what you want to do ? Given that task switches typically take several microseconds, the new code is pretty much identical to a busy loop, and the maximum sleep time is reduced significantly. Guenter > /* Read Interrupt source Register */ > val = inb(addr + 8); > /* Write Clear the interrupt source bits */ > -- > 2.30.2 >