On Tue, Aug 20, 2024 at 01:23:35PM +0300, Andy Shevchenko wrote: > On Tue, Aug 20, 2024 at 11:50:10AM +0530, Raag Jadav wrote: > > Add hwmon support for fan1_input attribute, which will expose fan speed > > in RPM. With this in place we can monitor fan speed using lm-sensors tool. > > > > $ sensors > > i915-pci-0300 > > Adapter: PCI adapter > > in0: 653.00 mV > > fan1: 3833 RPM > > power1: N/A (max = 43.00 W) > > energy1: 32.02 kJ > > > v2: Handle overflow, add mutex protection and ABI documentation > > Aesthetic adjustments (Riana) > > v3: Change rotations data type, ABI date and version > > v4: Fix wakeref leak > > Drop switch case and simplify hwm_fan_xx() (Andi) > > v5: Rework time calculation, aesthetic adjustments (Andy) > > v6: Drop overflow logic (Andy) > > Aesthetic adjustments (Badal) > > But it still has an issue with 64-bit division on 32-bit platforms, right? > > ... > > > + /* > > + * Calculate fan speed in RPM by time averaging two subsequent > > + * readings in minutes. > > + * RPM = number of rotations * msecs per minute / time in msecs > > + */ > > + *val = DIV_ROUND_UP(rotations * (MSEC_PER_SEC * 60), time); > > ...somewhere here? Use div64_u64() instead? Or is there a better alternative? Raag
