From mboxrd@z Thu Jan 1 00:00:00 1970 From: Guenter Roeck Date: Sun, 23 Feb 2014 16:26:53 +0000 Subject: Re: [lm-sensors] [PATCH v2 1/4] hwmon: (lm95245) Fix hysteresis temperatures Message-Id: <530A214D.60905@roeck-us.net> List-Id: References: <1393090212-24900-1-git-send-email-linux@roeck-us.net> In-Reply-To: <1393090212-24900-1-git-send-email-linux@roeck-us.net> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: lm-sensors@vger.kernel.org Hi Jean, On 02/23/2014 01:49 AM, Jean Delvare wrote: > Hi Guenter, > > On Sat, 22 Feb 2014 09:30:09 -0800, Guenter Roeck wrote: >> Hysteresis temperatures are defined as absolute temperatures, >> not as delta value from the critical temperatures. >> >> Signed-off-by: Guenter Roeck >> --- >> v2: Don't change indentation >> Don't call lm95245_update_device from set function >> In set function, actually write the calculated hysteresis >> instead of the entered value. >> >> drivers/hwmon/lm95245.c | 30 +++++++++++++++++++++--------- >> 1 file changed, 21 insertions(+), 9 deletions(-) >> >> diff --git a/drivers/hwmon/lm95245.c b/drivers/hwmon/lm95245.c >> index 3f0956e..d7bcea1 100644 >> --- a/drivers/hwmon/lm95245.c >> +++ b/drivers/hwmon/lm95245.c >> @@ -272,27 +272,39 @@ static ssize_t set_limit(struct device *dev, struct device_attribute *attr, >> return count; >> } >> >> +static ssize_t show_crit_hyst(struct device *dev, struct device_attribute *attr, >> + char *buf) >> +{ >> + struct lm95245_data *data = lm95245_update_device(dev); >> + int index = to_sensor_dev_attr(attr)->index; >> + int hyst = data->regs[index] - data->regs[8]; >> + >> + return snprintf(buf, PAGE_SIZE - 1, "%d\n", hyst * 1000); >> +} >> + >> static ssize_t set_crit_hyst(struct device *dev, struct device_attribute *attr, >> const char *buf, size_t count) >> { >> struct i2c_client *client = to_i2c_client(dev); >> struct lm95245_data *data = i2c_get_clientdata(client); >> + int index = to_sensor_dev_attr(attr)->index; >> unsigned long val; >> + long hyst; >> + int limit; > > Nitpicking: it makes little sense to have hyst and limit as different > types. > Ok, I'll change that. >> >> if (kstrtoul(buf, 10, &val) < 0) >> return -EINVAL; >> >> - val /= 1000; >> - >> - val = clamp_val(val, 0, 31); >> - >> mutex_lock(&data->update_lock); >> >> + limit = i2c_smbus_read_byte_data(client, lm95245_reg_address[index]); >> + hyst = limit - val / 1000; >> + hyst = clamp_val(hyst, 0, 31); > > Note that you don't actually need to hold the lock for that. Access to > the SMBus itself is already serialized at the bus driver level, and > you're not touching any field of the data structure (that's what the > lock is protecting.) > I think it was because the valid flag is cleared, to make sure the data is only re-read after the hysteresis register is written to. >> data->valid = 0; > > BTW do you have any idea why the whole cache is invalidated here? I'd > think that storing hyst as data->regs[8] would be enough? > It also ensures that the limit register value in the cache is current, but since that is not volatile it should not really make a difference. I'll change that and only update regs[8]. But then I do need the lock, or at least I think so. >> >> /* shared crit hysteresis */ >> i2c_smbus_write_byte_data(client, LM95245_REG_RW_COMMON_HYSTERESIS, >> - val); >> + hyst); >> >> mutex_unlock(&data->update_lock); >> >> @@ -378,16 +390,16 @@ static ssize_t set_interval(struct device *dev, struct device_attribute *attr, >> static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_input, NULL, 0); >> static SENSOR_DEVICE_ATTR(temp1_crit, S_IWUSR | S_IRUGO, show_limit, >> set_limit, 6); >> -static SENSOR_DEVICE_ATTR(temp1_crit_hyst, S_IWUSR | S_IRUGO, show_limit, >> - set_crit_hyst, 8); >> +static SENSOR_DEVICE_ATTR(temp1_crit_hyst, S_IWUSR | S_IRUGO, show_crit_hyst, >> + set_crit_hyst, 6); >> static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL, >> STATUS1_LOC); >> >> static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_input, NULL, 2); >> static SENSOR_DEVICE_ATTR(temp2_crit, S_IWUSR | S_IRUGO, show_limit, >> set_limit, 7); >> -static SENSOR_DEVICE_ATTR(temp2_crit_hyst, S_IWUSR | S_IRUGO, show_limit, >> - set_crit_hyst, 8); >> +static SENSOR_DEVICE_ATTR(temp2_crit_hyst, S_IWUSR | S_IRUGO, show_crit_hyst, >> + set_crit_hyst, 7); >> static SENSOR_DEVICE_ATTR(temp2_crit_alarm, S_IRUGO, show_alarm, NULL, >> STATUS1_RTCRIT); >> static SENSOR_DEVICE_ATTR(temp2_type, S_IWUSR | S_IRUGO, show_type, > > Reviewed-by: Jean Delvare > Thanks! Guenter _______________________________________________ lm-sensors mailing list lm-sensors@lm-sensors.org http://lists.lm-sensors.org/mailman/listinfo/lm-sensors