On Wed, Aug 07, 2024 at 02:24:27PM +0100, Andi Shyti wrote:
> Hi Raag,
>
> > +static umode_t
> > +hwm_fan_is_visible(const struct hwm_drvdata *ddat, u32 attr)
> > +{
> > + struct i915_hwmon *hwmon = ddat->hwmon;
> > +
> > + switch (attr) {
> > + case hwmon_fan_input:
> > + return i915_mmio_reg_valid(hwmon->rg.fan_speed) ? 0444 : 0;
> > + default:
> > + return 0;
> > + }
>
> Why do we need switch case here?
Just following the file conventions.
> Why can't this function become a single "return " line?
>
> > +}
> > +
> > +static int
> > +hwm_fan_read(struct hwm_drvdata *ddat, u32 attr, long *val)
> > +{
> > + struct i915_hwmon *hwmon = ddat->hwmon;
> > + struct hwm_fan_info *fi = &ddat->fi;
> > + u32 reg_val, pulses, time, time_now;
> > + intel_wakeref_t wakeref;
> > + long rotations;
> > + int ret = 0;
> > +
> > + switch (attr) {
> > + case hwmon_fan_input:
> > + with_intel_runtime_pm(ddat->uncore->rpm, wakeref) {
> > + mutex_lock(&hwmon->hwmon_lock);
> > +
> > + reg_val = intel_uncore_read(ddat->uncore,
> > hwmon->rg.fan_speed);
> > + time_now = jiffies_to_msecs(jiffies);
> > +
> > + /* Handle overflow */
> > + if (reg_val >= fi->reg_val_prev)
> > + pulses = reg_val - fi->reg_val_prev;
> > + else
> > + pulses = UINT_MAX - fi->reg_val_prev + reg_val;
> > +
> > + /*
> > + * HW register value is accumulated count of pulses from
> > + * PWM fan with the scale of 2 pulses per rotation.
> > + */
> > + rotations = pulses >> 1;
> > + time = time_now - fi->time_prev;
> > +
> > + if (unlikely(!time)) {
> > + ret = -EAGAIN;
> > + mutex_unlock(&hwmon->hwmon_lock);
> > + break;
> > + }
> > +
> > + /* Convert to minutes for calculating RPM */
> > + *val = DIV_ROUND_UP(rotations * (60 * MSEC_PER_SEC),
> > time);
> > +
> > + fi->reg_val_prev = reg_val;
> > + fi->time_prev = time_now;
> > +
> > + mutex_unlock(&hwmon->hwmon_lock);
> > + }
> > + return ret;
> > + default:
> > + return -EOPNOTSUPP;
> > + }
>
> same here, can we make this function:
>
> if (attr != hwmon_fan_input)
> return -EOPNOTSUPP;
>
> and then save all the indentation.
Makes sense for hwm_fan_read(). Let me try this.
> Are we expecting more cases here?
Not for now.
Raag
