From: Guenter Roeck <groeck7@xxxxxxxxx> on behalf of Guenter Roeck <linux@xxxxxxxxxxxx> Sent: Tuesday, March 4, 2025 12:12 PM >On 3/4/25 00:24, Maud Spierings via B4 Relay wrote: >> From: Maud Spierings <maudspierings@xxxxxxxxxxxxxx> >> >> Add the min and max temperature attributes as it is trivial for this >> driver. >> >> This can help with detecting implausible readings and indicates to users >> which range they can actually measure, so they will not set a trip point >> at a temperature higher than max or lower than min. >> >Unless I misunderstand the driver code, readings outside the table values >are never reported. Also, min/max are supposed to be alarm temperatures. >The reported values for min/max would be between -55 and +155 degrees C, >which does not make sense and has zero value for trip point usage. Regarding the driver not reporting values outside the table values: That does seem to be true and is good in my opinion, however currently 125 can mean 125 or something higher, with an indication of a max measurable temperature it can be determined that this is a max value and thus might have extra considerations. Regarding the meaning of attribues: It is difficult that the attributes do not have descriptions in include/linux/hwmon.h Is there an attribute that should be used to indicate this maximum measurable value to userspace? HWMON_T_HIGHEST/LOWEST? HWMON_T_RATED_MIN/MAX? Some extra ramblings: I want to have some indication of what the lowest and highest temperatures that the sensor can measure are. Imagine I set my trip point at 140 degrees, but the sensor can only measure up to 125, I would like there to be some feedback that this trip point can never be measured. Some kind of plausibility check may also be interesting. For example I have an ntc in an lvds display, if this display is disconnected it shuts down because the ADC reads zero, which means temp==temp_max. >NACK. > >Guenter Kind regards, Maud
