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 9EDECC4332F for ; Tue, 30 Nov 2021 14:34:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242224AbhK3OhZ (ORCPT ); Tue, 30 Nov 2021 09:37:25 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56492 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242223AbhK3OhY (ORCPT ); Tue, 30 Nov 2021 09:37:24 -0500 Received: from mail-oo1-xc30.google.com (mail-oo1-xc30.google.com [IPv6:2607:f8b0:4864:20::c30]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9B16BC061748; Tue, 30 Nov 2021 06:34:02 -0800 (PST) Received: by mail-oo1-xc30.google.com with SMTP id v30-20020a4a315e000000b002c52d555875so6750382oog.12; Tue, 30 Nov 2021 06:34:02 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=sender:subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=VzXaRiL/I8pc8Mlqw7AKcPRe1BRMY9UINIalpZhNbfw=; b=YTnEaa6u6j3wVnl4Cdg+jMNe/ODuZhL1Ses7vhU2tjfxJfu1zZxzQBCHhIx9qfXG4o eK+C11BeDdZhTS66um0KJkq//wWUHtZ5gyRnFOrWjmYXa761YHpMCqVgx7j0koA4+lKB U8qOVjBgBqbxoH1r8Sdg5kAip7/xr28yn9nBAkgbM15u/rzDIJ9LJCfdLrr1O/eJTouX ZIJA5op9Zm0tfNDKVabTfdDc4qyR0BDUltUngs1oeheDq314Hhw3V7HafZX1GIb5EC5X RStIsIE7SZnMtnjs1220CKspmZun3/XtxMgK7BC8WKj0CywPCmfYX688gbpwrkaTLhfD Wb0A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:sender:subject:to:cc:references:from:message-id :date:user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=VzXaRiL/I8pc8Mlqw7AKcPRe1BRMY9UINIalpZhNbfw=; b=TJkj6yDE6DRwptvq0VnO6F3IHa90a3Ewn7H9zllqOOL+K8Zx6h4WqZk6QdHTkxcLdv 4JCZbBaZzn5h0Fkr/qqQTktPxYyqZ6ZhSUdi0QzxtlDMxou9vDB1wXeKB9ouipnf7yCT VQh9z8lselmZwuEjZEElTHwiQFJ+BzVD0nBOxH2lnFthBVsVMrJiS/Q5CqTKRbpPt9jW BdbdiCK34Q3rljm++RUFmMyyj6bPYn9kqZuaenRgm9doMdGPB3vzOiISYV38gFmsJPKk DlS7pfXgptv9DZCM0RI+1WZKOB5LR1aZel+2sf2n+16p4GYeEEbqi9+/4gVdDFkDYtcY 0/3g== X-Gm-Message-State: AOAM532SvvzymAw1rHfzYm9+AmdvaHX4v4pVswJHccbfv2X64/njGWmk qtTEy9NUuvOd75jPsjifE7c5IzZRLCI= X-Google-Smtp-Source: ABdhPJxLV2vvhMd3qNDm9vAirWDFACsobvcg/sJ2rxtYXd6Tr5bBpod0yxH7Q+16n+p4UyEAko0VNA== X-Received: by 2002:a4a:a44b:: with SMTP id w11mr17324454ool.66.1638282841352; Tue, 30 Nov 2021 06:34:01 -0800 (PST) Received: from server.roeck-us.net ([2600:1700:e321:62f0:329c:23ff:fee3:9d7c]) by smtp.gmail.com with ESMTPSA id i3sm2759642ooq.39.2021.11.30.06.33.59 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 30 Nov 2021 06:34:00 -0800 (PST) Sender: Guenter Roeck Subject: Re: [PATCH] hwmon: (pwm-fan) Ensure the fan going on in .probe() To: Billy Tsai , b.zolnierkie@samsung.com, jdelvare@suse.com, u.kleine-koenig@pengutronix.de, linux-hwmon@vger.kernel.org, linux-kernel@vger.kernel.org Cc: BMC-SW@aspeedtech.com, stable@vger.kernel.org References: <20211130092212.17783-1-billy_tsai@aspeedtech.com> From: Guenter Roeck Message-ID: <175a4963-62dd-9213-1e92-74e8cd9829fc@roeck-us.net> Date: Tue, 30 Nov 2021 06:33:59 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.14.0 MIME-Version: 1.0 In-Reply-To: <20211130092212.17783-1-billy_tsai@aspeedtech.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/30/21 1:22 AM, Billy Tsai wrote: > Before commit 86585c61972f ("hwmon: (pwm-fan) stop using legacy > PWM functions and some cleanups") pwm_apply_state() was called > unconditionally in pwm_fan_probe(). In this commit this direct > call was replaced by a call to __set_pwm(ct, MAX_PWM) which > however is a noop if ctx->pwm_value already matches the value to > set. > After probe the fan is supposed to run at full speed, and the > internal driver state suggests it does, but this isn't asserted > and depending on bootloader and pwm low-level driver, the fan > might just be off. > So drop setting pwm_value to MAX_PWM to ensure the check in > __set_pwm doesn't make it exit early and the fan goes on as > intended. > > Cc: stable@vger.kernel.org > Fixes: 86585c61972f ("hwmon: (pwm-fan) stop using legacy PWM functions and some cleanups") > Signed-off-by: Billy Tsai I'll apply this patch, but _please_ version your patches in the future and provide a change log. Guenter > --- > drivers/hwmon/pwm-fan.c | 2 -- > 1 file changed, 2 deletions(-) > > diff --git a/drivers/hwmon/pwm-fan.c b/drivers/hwmon/pwm-fan.c > index 17518b4cab1b..f12b9a28a232 100644 > --- a/drivers/hwmon/pwm-fan.c > +++ b/drivers/hwmon/pwm-fan.c > @@ -336,8 +336,6 @@ static int pwm_fan_probe(struct platform_device *pdev) > return ret; > } > > - ctx->pwm_value = MAX_PWM; > - > pwm_init_state(ctx->pwm, &ctx->pwm_state); > > /* >