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? 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. Are we expecting more cases here? Andi