Messages in this thread | | | Subject | Re: [PATCH 05/10] hwmon: generic-pwm-tachometer: Add generic PWM based tachometer | From | Guenter Roeck <> | Date | Thu, 8 Mar 2018 06:31:24 -0800 |
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On 03/07/2018 10:06 PM, Laxman Dewangan wrote: > > > On Wednesday 07 March 2018 07:50 PM, Guenter Roeck wrote: >> On 03/07/2018 01:47 AM, Rajkumar Rampelli wrote: >>> >>>> >>>> While I am not opposed to ABI changes, the merits of those would need to be >>>> discussed on the mailing list. But replacing "fan1_input" with "rpm" is >>>> not an acceptable ABI change, even if it may measure something that turns >>>> but isn't a fan. >>>> >>>> If this _is_ in fact supposed to be used for something else but fans, we >>>> would have to discuss what that might be, and if hwmon is the appropriate >>>> subsystem to measure and report it. This does to some degree lead back to >>>> my concern of having the "fan" part of this patch series in the pwm core. >>>> I am still not sure if that makes sense. >>>> >>>> Thanks, >>>> Guenter >>> I am planning to add tachometer support in pwm-fan.c driver (drivers/hwmon/) instead of adding new generic-pwm-tachometer.c driver. Measuring RPM value will be done in pwm-fan driver itself using pwm capture feature and will add new sysfs attributes under this driver to report rpm value of fan. >> >> There is an existing attribute to report the RPM of fans. It is called fan[1..n]_input. >> >> "replacing "fan1_input" with "rpm" is not an acceptable ABI change" >> >> Preemptive NACK. > > The RPM is measured speed via PWM signal capture which is output from fan. > So should we have the fan[1..n]_output_rpm? >
No. I hear you clearly that you for some reason dislike fan[1..n]_input. While ABIs are not always to our liking, that doesn't mean that we get to change them at our whim. If that is not acceptable for you, I can't help you. And you can't change inX_input to inX_voltage either, sorry.
Guenter
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