Messages in this thread | | | Date | Sun, 21 Dec 2014 03:57:08 -0800 | From | Guenter Roeck <> | Subject | Re: [PATCH v3] i8k: Autodetect maximal fan speed and fan RPM multiplier |
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On 12/21/2014 01:20 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 <pali.rohar@gmail.com> > Tested-by: Pali Rohár <pali.rohar@gmail.com> > --- > drivers/char/i8k.c | 89 ++++++++++++++++++++++++++++++++++++++++++++-------- > 1 file changed, 76 insertions(+), 13 deletions(-) > > diff --git a/drivers/char/i8k.c b/drivers/char/i8k.c > index 48d701c..ce2147c 100644 > --- a/drivers/char/i8k.c > +++ b/drivers/char/i8k.c > @@ -6,6 +6,7 @@ > * Hwmon integration: > * Copyright (C) 2011 Jean Delvare <jdelvare@suse.de> > * Copyright (C) 2013, 2014 Guenter Roeck <linux@roeck-us.net> > + * Copyright (C) 2014 Pali Rohár <pali.rohar@gmail.com> > * > * 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 +43,13 @@ > #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_MAX_RPM 30000 > #define I8K_MAX_TEMP 127 > > #define I8K_FN_NONE 0x00 > @@ -64,7 +66,7 @@ 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_fan_mult = 30;
Why did you drop I8K_FAN_MULT ?
> static int i8k_pwm_mult; > static int i8k_fan_max = I8K_FAN_HIGH; > > @@ -95,13 +97,13 @@ 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); > @@ -276,6 +278,17 @@ static int i8k_get_fan_speed(int 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, }; > + > + regs.ebx = (fan & 0xff) | (speed << 8); > + return i8k_smm(®s) ? : (regs.eax & 0xffff) * i8k_fan_mult; > +} > + > +/* > * Set the fan speed (off, low, high). Returns the new fan status. > */ > static int i8k_set_fan(int fan, int speed) > @@ -854,7 +867,9 @@ MODULE_DEVICE_TABLE(dmi, i8k_dmi_table); > */ > static int __init i8k_probe(void) > { > + const struct i8k_config_data *conf;
Why did you move this variable declaration ?
> const struct dmi_system_id *id; > + int fan, val, ret; > > /* > * Get DMI information > @@ -883,19 +898,67 @@ 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)
I still don't see the value in accepting fan_mult < 0 (compeared to == 0).
> + fan_mult = conf->fan_mult; > + if (fan_max <= 0 && conf->fan_max > 0)
Same for fan_max < 0.
> + fan_max = conf->fan_max; > + } > > - 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) {
Same here.
> + /* > + * Autodetect maximal fan speed value > + * Speed value is valid if i8k_get_fan_nominal_speed() not fail > + */ > + for (fan = 0; fan < 2; ++fan) { > + for (val = 1; val < 256; ++val) { > + if (i8k_get_fan_nominal_speed(fan, val) < 0) > + break; > + fan_max = val; /* Must not be 0 */ > + } > + if (fan_max != 0) { > + i8k_fan_max = fan_max; > + break; > + } > + } > + } else { > + /* Maximal fan speed was specified in module param or in dmi */ > + i8k_fan_max = fan_max; > } > + > i8k_pwm_mult = DIV_ROUND_UP(255, i8k_fan_max); > > + if (fan_mult <= 0) {
Same here.
Thanks, Guenter
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