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 BDC56C433F5 for ; Tue, 26 Apr 2022 20:33:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1354986AbiDZUgv (ORCPT ); Tue, 26 Apr 2022 16:36:51 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45998 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1355034AbiDZUgq (ORCPT ); Tue, 26 Apr 2022 16:36:46 -0400 Received: from mail-oa1-x2a.google.com (mail-oa1-x2a.google.com [IPv6:2001:4860:4864:20::2a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DC1781AAB63; Tue, 26 Apr 2022 13:33:28 -0700 (PDT) Received: by mail-oa1-x2a.google.com with SMTP id 586e51a60fabf-e2fa360f6dso20645354fac.2; Tue, 26 Apr 2022 13:33:28 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=sender:date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=VZ4m53/siNJy3szXTYThcPOYpErMJB0pa/nMP6ZGHk4=; b=cixBLl8WkxFLsGtzEnwriihAF1Snv3H0DEFiF30yyvsbVvX3BaQyEkeXtgM/nyizi0 gykhgLjvfbL3EM2B+gFp0F3lsS85RRk3wDg7bT+LPzl4zudWhSGNVR5e6Z1atWBSkGu/ L5ZbyiRG7Ob0We2rZCmZJvWzUCAIW0c2ASFr7s8r6asqr+FcGTU8Q/t6X6w+pIDBuiUn /5gnK5JcPreXWbThuXvA6fXGBc0GmCZgTalNWS4Yl2L9+6zHvb/vOKK3G6eA8LyBSUWD NqbgDYC3m0ZO+l+65u5/J4IrGP+jfAx0PJs18VC/Cj0DK5MXPPzW3ChzT2xYs0NwbtPw kvdg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:sender:date:from:to:cc:subject:message-id :references:mime-version:content-disposition:in-reply-to; bh=VZ4m53/siNJy3szXTYThcPOYpErMJB0pa/nMP6ZGHk4=; b=auvDg0zrQFJ4ZIaJjBVPZT0/UBz3B3nHqErO1iCT/iFukguXUUXx5yO0sLL6PSXGDy nmRZrIupFhlohJF/A1opntQAR7lGf9P0ST2ByFnFE8PXmnphaev9wNb8eVxgG8ZMDWvt J3ghWswT3fHbpm0jsvaMICHtlSaaBGupzd7nc4wZcBNvjDCc6Pz7RxDPgfi8Fs6lLgGV r2d43hFF1TjPJ4Z/G1JEEZTUhttRV76n9Fcl5oaAnvlNasHACwRYR66Gad1URb9TPLMZ G7gfILiG/bWvKXdiEkkPkWkd0dpD7gy8VwB3lIXfW5JnZmHzcS11hioZDOjOkZGEaZ8C hLDQ== X-Gm-Message-State: AOAM533SMq735l06scb4hhTqman89Q9BOsaqmIEf3Z8r6bZNsoAqqrh5 VvYd2+lAlb3kiQytl0AvFdo= X-Google-Smtp-Source: ABdhPJyCtcfZ1jSPkur0xtPK8uPf0o8G0+H6j5Ooe/MmqE+1nIUd0FFIDjFF1cTIEkkqrZTFBF+0HA== X-Received: by 2002:a05:6870:c1cd:b0:e6:757f:9a04 with SMTP id i13-20020a056870c1cd00b000e6757f9a04mr10077260oad.265.1651005208188; Tue, 26 Apr 2022 13:33:28 -0700 (PDT) Received: from server.roeck-us.net ([2600:1700:e321:62f0:329c:23ff:fee3:9d7c]) by smtp.gmail.com with ESMTPSA id k15-20020a4a2a0f000000b0033a34a057c8sm5985507oof.11.2022.04.26.13.33.27 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 26 Apr 2022 13:33:27 -0700 (PDT) Sender: Guenter Roeck Date: Tue, 26 Apr 2022 13:33:25 -0700 From: Guenter Roeck To: Armin Wolf Cc: pali@kernel.org, jdelvare@suse.com, linux-hwmon@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/3] hwmon: (dell-smm) Avoid unnecessary SMM calls during init Message-ID: <20220426203325.GP4093517@roeck-us.net> References: <20220426200320.399435-1-W_Armin@gmx.de> <20220426200320.399435-2-W_Armin@gmx.de> <20220426202048.GO4093517@roeck-us.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220426202048.GO4093517@roeck-us.net> Precedence: bulk List-ID: X-Mailing-List: linux-hwmon@vger.kernel.org On Tue, Apr 26, 2022 at 01:20:48PM -0700, Guenter Roeck wrote: > On Tue, Apr 26, 2022 at 10:03:18PM +0200, Armin Wolf wrote: > > When the driver tries to detect the fan multiplier during > > module initialisation, it issues one SMM call for each fan. > > Those SMM calls are however redundant and also try to query > > fans which may not be present. > > Fix that by detecting the fan multiplier during hwmon > > initialisation when no extra SMM calls are needed. > > Also dont assume the last nominal speed entry to be the > > biggest and instead check all entries. > > > > Signed-off-by: Armin Wolf > > --- > > drivers/hwmon/dell-smm-hwmon.c | 37 +++++++++++++--------------------- > > 1 file changed, 14 insertions(+), 23 deletions(-) > > > > diff --git a/drivers/hwmon/dell-smm-hwmon.c b/drivers/hwmon/dell-smm-hwmon.c > > index 30b6f0c28093..202ee884de9e 100644 > > --- a/drivers/hwmon/dell-smm-hwmon.c > > +++ b/drivers/hwmon/dell-smm-hwmon.c > > @@ -50,7 +50,7 @@ > > #define I8K_SMM_GET_DELL_SIG2 0xffa3 > > > > #define I8K_FAN_MULT 30 > > -#define I8K_FAN_MAX_RPM 30000 > > +#define I8K_FAN_RPM_THRESHOLD 1000 > > #define I8K_MAX_TEMP 127 > > > > #define I8K_FN_NONE 0x00 > > @@ -326,7 +326,7 @@ static int __init i8k_get_fan_nominal_speed(const struct dell_smm_data *data, u8 > > if (data->disallow_fan_support) > > return -EINVAL; > > > > - return i8k_smm(®s) ? : (regs.eax & 0xffff) * data->i8k_fan_mult; > > + return i8k_smm(®s) ? : (regs.eax & 0xffff); > > } > > > > /* > > @@ -776,6 +776,7 @@ static int dell_smm_read(struct device *dev, enum hwmon_sensor_types type, u32 a > > long *val) > > { > > struct dell_smm_data *data = dev_get_drvdata(dev); > > + int mult = data->i8k_fan_mult; > > int ret; > > > > switch (type) { > > @@ -804,11 +805,11 @@ static int dell_smm_read(struct device *dev, enum hwmon_sensor_types type, u32 a > > > > return 0; > > case hwmon_fan_min: > > - *val = data->fan_nominal_speed[channel][0]; > > + *val = data->fan_nominal_speed[channel][0] * mult; > > > > return 0; > > case hwmon_fan_max: > > - *val = data->fan_nominal_speed[channel][data->i8k_fan_max]; > > + *val = data->fan_nominal_speed[channel][data->i8k_fan_max] * mult; > > > > return 0; > > case hwmon_fan_target: > > @@ -819,7 +820,7 @@ static int dell_smm_read(struct device *dev, enum hwmon_sensor_types type, u32 a > > if (ret > data->i8k_fan_max) > > ret = data->i8k_fan_max; > > > > - *val = data->fan_nominal_speed[channel][ret]; > > + *val = data->fan_nominal_speed[channel][ret] * mult; > > > > return 0; > > default: > > @@ -1071,6 +1072,13 @@ static int __init dell_smm_init_hwmon(struct device *dev) > > break; > > } > > data->fan_nominal_speed[i][state] = err; > > + /* > > + * Autodetect fan multiplier based on nominal rpm if multiplier > > + * was not specified as module param or in DMI. If fan reports > > + * rpm value too high then set multiplier to 1. > > + */ > > + if (!fan_mult && err > I8K_FAN_RPM_THRESHOLD) > > + data->i8k_fan_mult = 1; > > } > > } > > > > @@ -1359,7 +1367,6 @@ static int __init dell_smm_probe(struct platform_device *pdev) > > struct dell_smm_data *data; > > const struct dmi_system_id *id, *fan_control; > > int ret; > > - u8 fan; > > > > data = devm_kzalloc(&pdev->dev, sizeof(struct dell_smm_data), GFP_KERNEL); > > if (!data) > > @@ -1414,24 +1421,8 @@ static int __init dell_smm_probe(struct platform_device *pdev) > > dev_info(&pdev->dev, "enabling support for setting automatic/manual fan control\n"); > > } > > > > - if (!fan_mult) { > > - /* > > - * Autodetect fan multiplier based on nominal rpm > > - * If fan reports rpm value too high then set multiplier to 1 > > - */ > > - for (fan = 0; fan < DELL_SMM_NO_FANS; ++fan) { > > - ret = i8k_get_fan_nominal_speed(data, fan, data->i8k_fan_max); > > - if (ret < 0) > > - continue; > > - > > - if (ret > I8K_FAN_MAX_RPM) > > - data->i8k_fan_mult = 1; > > - break; > > - } > > - } else { > > - /* Fan multiplier was specified in module param or in dmi */ > > + if (fan_mult) > > Might as well drop the if statement here. > Never mind, I see that is removed later anyway. Guenter > > data->i8k_fan_mult = fan_mult; > > - } > > > > ret = dell_smm_init_hwmon(&pdev->dev); > > if (ret) > > -- > > 2.30.2 > >