Messages in this thread | | | Date | Tue, 9 Dec 2014 12:20:23 -0800 | From | Guenter Roeck <> | Subject | Re: [PATCH 2/3] i8k: Autodetect maximal fan speed and fan RPM multiplier |
| |
On Tue, Dec 09, 2014 at 09:07:00PM +0100, Pali Rohár wrote: > This patch adds new function i8k_get_fan_nominal_rpm() 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 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 was 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> > --- > I tested this patch only on my Dell Latitude E6440 and autodetection worked fine > Before appying this patch it should be tested on some other dell machines too > but if machine does not support i8k_get_fan_nominal_rpm() driver should fallback > to old values. So patch should be without regressions.
It looks like many of your error checks are unnecessary. Why did you add those ?
Please refrain from adding unnecessary code.
Guenter
> --- > drivers/char/i8k.c | 122 ++++++++++++++++++++++++++++++++++++++-------- > include/uapi/linux/i8k.h | 4 +- > 2 files changed, 104 insertions(+), 22 deletions(-) > > diff --git a/drivers/char/i8k.c b/drivers/char/i8k.c > index 31e4beb..8bdbed2 100644 > --- a/drivers/char/i8k.c > +++ b/drivers/char/i8k.c > @@ -42,12 +42,14 @@ > #define I8K_SMM_GET_FAN_SPEED 0x00a3 > #define I8K_SMM_SET_FAN_SPEED 0x01a3 > #define I8K_SMM_GET_FAN_RPM 0x02a3 > +#define I8K_SMM_GET_FAN_NOM_RPM 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 +66,9 @@ 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[I8K_FAN_COUNT]; > +static int i8k_pwm_mult[I8K_FAN_COUNT]; > +static int i8k_fan_max[I8K_FAN_COUNT]; > > #define I8K_HWMON_HAVE_TEMP1 (1 << 0) > #define I8K_HWMON_HAVE_TEMP2 (1 << 1) > @@ -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 rpm with"); > +MODULE_PARM_DESC(fan_mult, "Factor to multiply fan rpm 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 +273,25 @@ static int i8k_get_fan_rpm(int fan) > { > struct smm_regs regs = { .eax = I8K_SMM_GET_FAN_RPM, }; > > + if (fan < 0 || fan >= I8K_FAN_COUNT) > + 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_rpm(int fan, int speed) > +{ > + struct smm_regs regs = { .eax = I8K_SMM_GET_FAN_NOM_RPM, }; > + > + if (fan < 0 || fan >= I8K_FAN_COUNT) > + return -EINVAL; > + > + regs.ebx = (fan & 0xff) | (speed << 8); > + return i8k_smm(®s) ? : (regs.eax & 0xffff) * i8k_fan_mult[fan]; > } > > /* > @@ -282,9 +301,12 @@ static int i8k_set_fan_speed(int fan, int speed) > { > struct smm_regs regs = { .eax = I8K_SMM_SET_FAN_SPEED, }; > > - 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 < I8K_FAN_COUNT && speed > i8k_fan_max[fan]) > + speed = i8k_fan_max[fan]; > > + regs.ebx = (fan & 0xff) | (speed << 8); > return i8k_smm(®s) ? : i8k_get_fan_speed(fan); > } > > @@ -559,10 +581,14 @@ static ssize_t i8k_hwmon_show_pwm(struct device *dev, > int index = to_sensor_dev_attr(devattr)->index; > int fan_speed; > > + if (index < 0 || index >= I8K_FAN_COUNT) > + return -EINVAL; > + > fan_speed = i8k_get_fan_speed(index); > if (fan_speed < 0) > return -EIO; > - return sprintf(buf, "%d\n", clamp_val(fan_speed * i8k_pwm_mult, 0, 255)); > + return sprintf(buf, "%d\n", clamp_val(fan_speed * i8k_pwm_mult[index], > + 0, 255)); > } > > static ssize_t i8k_hwmon_set_pwm(struct device *dev, > @@ -573,10 +599,14 @@ static ssize_t i8k_hwmon_set_pwm(struct device *dev, > unsigned long val; > int err; > > + if (index < 0 || index >= I8K_FAN_COUNT) > + return -EINVAL; > + > 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_speed(index, val); > @@ -854,7 +884,9 @@ 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 +915,66 @@ 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 == 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_mult <= 0) { > + /* > + * 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 > + */ > + for (fan = 0; fan < I8K_FAN_COUNT; ++fan) { > + i8k_fan_mult[fan] = I8K_FAN_DEFAULT_MULT; > + for (val = 0; val < 256; ++val) { > + ret = i8k_get_fan_nominal_rpm(fan, val); > + if (ret > I8K_FAN_MAX_RPM) { > + i8k_fan_mult[fan] = 1; > + break; > + } else if (ret < 0) { > + break; > + } > + } > + } > + } else { > + /* Fan multiplier was specified in module param or in dmi */ > + for (fan = 0; fan < I8K_FAN_COUNT; ++fan) > + i8k_fan_mult[fan] = fan_mult; > } > - i8k_pwm_mult = DIV_ROUND_UP(255, i8k_fan_max); > + > + if (fan_max <= 0) { > + /* > + * Autodetect maximal fan speed value for each fan > + * Speed value is valid if i8k_get_fan_nominal_rpm() not fail > + */ > + for (fan = 0; fan < I8K_FAN_COUNT; ++fan) { > + for (val = 0; val < 256; ++val) { > + if (i8k_get_fan_nominal_rpm(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; > + } > + } else { > + /* Maximal fan speed was specified in module param or in dmi */ > + for (fan = 0; fan < I8K_FAN_COUNT; ++fan) > + i8k_fan_max[fan] = fan_max; > + } > + > + for (fan = 0; fan < I8K_FAN_COUNT; ++fan) > + i8k_pwm_mult[fan] = DIV_ROUND_UP(255, i8k_fan_max[fan]); > > return 0; > } > diff --git a/include/uapi/linux/i8k.h b/include/uapi/linux/i8k.h > index 133d02f..60ef0ea 100644 > --- a/include/uapi/linux/i8k.h > +++ b/include/uapi/linux/i8k.h > @@ -29,8 +29,10 @@ > #define I8K_GET_FAN _IOWR('i', 0x86, size_t) > #define I8K_SET_FAN _IOWR('i', 0x87, size_t) > > -#define I8K_FAN_LEFT 1 > #define I8K_FAN_RIGHT 0 > +#define I8K_FAN_LEFT 1 > +#define I8K_FAN_COUNT (I8K_FAN_LEFT + 1) > + > #define I8K_FAN_OFF 0 > #define I8K_FAN_LOW 1 > #define I8K_FAN_HIGH 2 > -- > 1.7.9.5 >
| |