From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751508AbaLTSjF (ORCPT ); Sat, 20 Dec 2014 13:39:05 -0500 Received: from bh-25.webhostbox.net ([208.91.199.152]:58509 "EHLO bh-25.webhostbox.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750981AbaLTSjD (ORCPT ); Sat, 20 Dec 2014 13:39:03 -0500 Message-ID: <5495C228.4030400@roeck-us.net> Date: Sat, 20 Dec 2014 10:38:32 -0800 From: Guenter Roeck User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.3.0 MIME-Version: 1.0 To: =?UTF-8?B?UGFsaSBSb2jDoXI=?= , Arnd Bergmann , Greg Kroah-Hartman CC: linux-kernel@vger.kernel.org, Valdis.Kletnieks@vt.edu, Steven Honeyman , Jean Delvare , Gabriele Mazzotta , Jochen Eisinger Subject: Re: [PATCH v2 1/2] i8k: Autodetect maximal fan speed and fan RPM multiplier References: <1418155621-21644-1-git-send-email-pali.rohar@gmail.com> <1419012268-20805-1-git-send-email-pali.rohar@gmail.com> In-Reply-To: <1419012268-20805-1-git-send-email-pali.rohar@gmail.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit X-Authenticated_sender: linux@roeck-us.net X-OutGoing-Spam-Status: No, score=-1.0 X-CTCH-PVer: 0000001 X-CTCH-Spam: Unknown X-CTCH-VOD: Unknown X-CTCH-Flags: 0 X-CTCH-RefID: str=0001.0A020205.5495C246.005C,ss=1,re=0.001,recu=0.000,reip=0.000,cl=1,cld=1,fgs=0 X-CTCH-Score: 0.001 X-CTCH-ScoreCust: 0.000 X-CTCH-Rules: C_4847, X-CTCH-SenderID: linux@roeck-us.net X-CTCH-SenderID-Flags: 0 X-CTCH-SenderID-TotalMessages: 6 X-CTCH-SenderID-TotalSpam: 0 X-CTCH-SenderID-TotalSuspected: 0 X-CTCH-SenderID-TotalConfirmed: 0 X-CTCH-SenderID-TotalBulk: 0 X-CTCH-SenderID-TotalVirus: 0 X-CTCH-SenderID-TotalRecipients: 0 X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - bh-25.webhostbox.net X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - roeck-us.net X-Get-Message-Sender-Via: bh-25.webhostbox.net: mailgid no entry from get_relayhosts_entry X-Source: X-Source-Args: X-Source-Dir: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/19/2014 10:04 AM, Pali Rohár wrote: > This patch adds new function i8k_get_fan_nominal_speed() for doing SMM call > which will return nominal fan RPM for specified fan speed. It returns nominal > RPM value at which fan operate when speed (0, 1, 2, 3) is set. It looks like > RPM value is not accurate, but still provides very useful information. > > First it can be used to validate if certain fan speed could be accepted by SMM > for setting fan speed and we can use this routine to detect maximal fan speed. > > Second it returns RPM value, so we can check if value looks correct with > multiplier 30 or multiplier 1 (until now only these two multiplier were used). > If RPM value with multiplier 30 is too high, then multiplier 1 is used. > > In case when SMM reports that new function is not supported we will fallback > to old hardcoded values. Maximal fan speed would be 2 and RPM multiplier 30. > > Signed-off-by: Pali Rohár > Tested-By: Pali Rohár > Tested-By: Steven Honeyman > Tested-By: Valdis Kletnieks > --- > drivers/char/i8k.c | 126 +++++++++++++++++++++++++++++++++++++++++++--------- > 1 file changed, 105 insertions(+), 21 deletions(-) > > diff --git a/drivers/char/i8k.c b/drivers/char/i8k.c > index 48d701c..094a6b8 100644 > --- a/drivers/char/i8k.c > +++ b/drivers/char/i8k.c > @@ -6,6 +6,7 @@ > * Hwmon integration: > * Copyright (C) 2011 Jean Delvare > * Copyright (C) 2013, 2014 Guenter Roeck > + * Copyright (C) 2014 Pali Rohár > * > * This program is free software; you can redistribute it and/or modify it > * under the terms of the GNU General Public License as published by the > @@ -42,12 +43,14 @@ > #define I8K_SMM_SET_FAN 0x01a3 > #define I8K_SMM_GET_FAN 0x00a3 > #define I8K_SMM_GET_SPEED 0x02a3 > +#define I8K_SMM_GET_NOM_SPEED 0x04a3 > #define I8K_SMM_GET_TEMP 0x10a3 > #define I8K_SMM_GET_TEMP_TYPE 0x11a3 > #define I8K_SMM_GET_DELL_SIG1 0xfea3 > #define I8K_SMM_GET_DELL_SIG2 0xffa3 > > -#define I8K_FAN_MULT 30 > +#define I8K_FAN_DEFAULT_MULT 30 > +#define I8K_FAN_MAX_RPM 30000 > #define I8K_MAX_TEMP 127 > > #define I8K_FN_NONE 0x00 > @@ -64,9 +67,9 @@ static DEFINE_MUTEX(i8k_mutex); > static char bios_version[4]; > static struct device *i8k_hwmon_dev; > static u32 i8k_hwmon_flags; > -static int i8k_fan_mult; > -static int i8k_pwm_mult; > -static int i8k_fan_max = I8K_FAN_HIGH; > +static int i8k_fan_mult[2]; > +static int i8k_pwm_mult[2]; > +static int i8k_fan_max[2]; > > #define I8K_HWMON_HAVE_TEMP1 (1 << 0) > #define I8K_HWMON_HAVE_TEMP2 (1 << 1) > @@ -95,13 +98,13 @@ static bool power_status; > module_param(power_status, bool, 0600); > MODULE_PARM_DESC(power_status, "Report power status in /proc/i8k"); > > -static int fan_mult = I8K_FAN_MULT; > +static int fan_mult; > module_param(fan_mult, int, 0); > -MODULE_PARM_DESC(fan_mult, "Factor to multiply fan speed with"); > +MODULE_PARM_DESC(fan_mult, "Factor to multiply fan speed with (default: autodetect)"); > > -static int fan_max = I8K_FAN_HIGH; > +static int fan_max; > module_param(fan_max, int, 0); > -MODULE_PARM_DESC(fan_max, "Maximum configurable fan speed"); > +MODULE_PARM_DESC(fan_max, "Maximum configurable fan speed (default: autodetect)"); > > static int i8k_open_fs(struct inode *inode, struct file *file); > static long i8k_ioctl(struct file *, unsigned int, unsigned long); > @@ -271,8 +274,25 @@ static int i8k_get_fan_speed(int fan) > { > struct smm_regs regs = { .eax = I8K_SMM_GET_SPEED, }; > > + if (fan < 0 || fan >= ARRAY_SIZE(i8k_fan_mult)) > + return -EINVAL; > + > regs.ebx = fan & 0xff; > - return i8k_smm(®s) ? : (regs.eax & 0xffff) * i8k_fan_mult; > + return i8k_smm(®s) ? : (regs.eax & 0xffff) * i8k_fan_mult[fan]; > +} > + > +/* > + * Read the fan nominal rpm for specific fan speed. > + */ > +static int i8k_get_fan_nominal_speed(int fan, int speed) > +{ > + struct smm_regs regs = { .eax = I8K_SMM_GET_NOM_SPEED, }; > + > + if (fan < 0 || fan >= ARRAY_SIZE(i8k_fan_mult)) > + return -EINVAL; > + > + regs.ebx = (fan & 0xff) | (speed << 8); > + return i8k_smm(®s) ? : (regs.eax & 0xffff) * i8k_fan_mult[fan]; > } > > /* > @@ -282,9 +302,12 @@ static int i8k_set_fan(int fan, int speed) > { > struct smm_regs regs = { .eax = I8K_SMM_SET_FAN, }; > > - speed = (speed < 0) ? 0 : ((speed > i8k_fan_max) ? i8k_fan_max : speed); > - regs.ebx = (fan & 0xff) | (speed << 8); > + if (speed < 0) > + speed = 0; > + if (fan >= 0 && fan < ARRAY_SIZE(i8k_fan_max) && speed > i8k_fan_max[fan]) > + speed = i8k_fan_max[fan]; > > + regs.ebx = (fan & 0xff) | (speed << 8); > return i8k_smm(®s) ? : i8k_get_fan_status(fan); > } > > @@ -562,7 +585,8 @@ static ssize_t i8k_hwmon_show_pwm(struct device *dev, > status = i8k_get_fan_status(index); > if (status < 0) > return -EIO; > - return sprintf(buf, "%d\n", clamp_val(status * i8k_pwm_mult, 0, 255)); > + return sprintf(buf, "%d\n", clamp_val(status * i8k_pwm_mult[index], > + 0, 255)); > } > > static ssize_t i8k_hwmon_set_pwm(struct device *dev, > @@ -576,7 +600,8 @@ static ssize_t i8k_hwmon_set_pwm(struct device *dev, > err = kstrtoul(buf, 10, &val); > if (err) > return err; > - val = clamp_val(DIV_ROUND_CLOSEST(val, i8k_pwm_mult), 0, i8k_fan_max); > + val = clamp_val(DIV_ROUND_CLOSEST(val, i8k_pwm_mult[index]), 0, > + i8k_fan_max[index]); > > mutex_lock(&i8k_mutex); > err = i8k_set_fan(index, val); > @@ -854,7 +879,9 @@ MODULE_DEVICE_TABLE(dmi, i8k_dmi_table); > */ > static int __init i8k_probe(void) > { > + const struct i8k_config_data *conf; > const struct dmi_system_id *id; > + int fan, val, ret; > > /* > * Get DMI information > @@ -883,18 +910,75 @@ static int __init i8k_probe(void) > return -ENODEV; > } > > - i8k_fan_mult = fan_mult; > - i8k_fan_max = fan_max ? : I8K_FAN_HIGH; /* Must not be 0 */ > + /* > + * Autodetect fan multiplier and maximal fan speed from dmi config > + * Values specified in module parameters override values from dmi > + */ > id = dmi_first_match(i8k_dmi_table); > if (id && id->driver_data) { > - const struct i8k_config_data *conf = id->driver_data; > + conf = id->driver_data; > + if (fan_mult <= 0 && conf->fan_mult > 0) > + fan_mult = conf->fan_mult; > + if (fan_max <= 0 && conf->fan_max > 0) > + fan_max = conf->fan_max; > + } > + > + if (fan_mult <= 0) { Wonder what to do in the < 0 case. It might be better to make the variable and the module parameter an unsigned int to cover that case, since a negative multiplier doesn't really make sense. Same for fan_max. > + /* > + * Autodetect fan multiplier for each fan based on nominal rpm > + * First set default fan multiplier for each fan > + * And if it reports rpm value too high then set multiplier to 1 > + * > + * Try also setting multiplier from current rpm, but this will > + * work only in case when fan is not turned off. It is better > + * then nothing for machines which does not support nominal rpm > + * SMM function. > + */ > + for (fan = 0; fan < ARRAY_SIZE(i8k_fan_mult); ++fan) { > + i8k_fan_mult[fan] = I8K_FAN_DEFAULT_MULT; > + if (i8k_get_fan_speed(fan) > I8K_FAN_MAX_RPM) { > + i8k_fan_mult[fan] = 1; > + continue; > + } What if i8k_get_fan_speed(fan) returns an error ? Doesn't that imply that the fan does not exist, and that you would not need the second loop in the first place ? > + for (val = 0; val < 256; ++val) { > + ret = i8k_get_fan_nominal_speed(fan, val); > + if (ret > I8K_FAN_MAX_RPM) { > + i8k_fan_mult[fan] = 1; > + break; > + } else if (ret < 0) { > + break; > + } Traditionally error checks come first. > + } > + } > + } else { > + /* Fan multiplier was specified in module param or in dmi */ > + for (fan = 0; fan < ARRAY_SIZE(i8k_fan_mult); ++fan) > + i8k_fan_mult[fan] = fan_mult; > + } > > - if (fan_mult == I8K_FAN_MULT && conf->fan_mult) > - i8k_fan_mult = conf->fan_mult; > - if (fan_max == I8K_FAN_HIGH && conf->fan_max) > - i8k_fan_max = conf->fan_max; > + if (fan_max <= 0) { > + /* > + * Autodetect maximal fan speed value for each fan > + * Speed value is valid if i8k_get_fan_nominal_speed() not fail > + */ > + for (fan = 0; fan < ARRAY_SIZE(i8k_fan_max); ++fan) { > + for (val = 0; val < 256; ++val) { > + if (i8k_get_fan_nominal_speed(fan, val) < 0) > + break; > + } > + --val; /* set last value which not failed */ > + if (val <= 0) /* Must not be 0 (and non negative) */ > + val = I8K_FAN_HIGH; > + i8k_fan_max[fan] = val; I kind of dislike that you are (at least potentially) looping through all the nominal speeds twice; not sure how long that will delay the boot process. I don't know if or how that can be solved easily, though. Either case, I would prefer something like i8k_fan_max = I8K_FAN_HIGH; for (val = 0; val < 256; ++val) { if (i8k_get_fan_nominal_speed(fan, val) < 0) break; i8k_fan_max = val; } since that would take care of all the meddling at the end. > + } > + } else { > + /* Maximal fan speed was specified in module param or in dmi */ > + for (fan = 0; fan < ARRAY_SIZE(i8k_fan_max); ++fan) > + i8k_fan_max[fan] = fan_max; > } Overall I think it would make sense to move the auto-detection code to a separate function. This is getting a bit large to have it all in a single function. Thanks, Guenter > - i8k_pwm_mult = DIV_ROUND_UP(255, i8k_fan_max); > + > + for (fan = 0; fan < ARRAY_SIZE(i8k_pwm_mult); ++fan) > + i8k_pwm_mult[fan] = DIV_ROUND_UP(255, i8k_fan_max[fan]); > > return 0; > } >