On Wed, Aug 28, 2024 at 04:59:00PM +0300, Andy Shevchenko wrote:
> On Wed, Aug 28, 2024 at 10:15:12AM +0530, Raag Jadav wrote:
> > Add hwmon support for temp1_input attribute, which will expose package
> > temperature in millidegree Celsius. With this in place we can monitor
> > package temperature using lm-sensors tool.
> >
> > $ sensors
> > i915-pci-0300
> > Adapter: PCI adapter
> > in0: 990.00 mV
> > fan1: 1260 RPM
> > temp1: +45.0°C
> > power1: N/A (max = 35.00 W)
> > energy1: 12.62 kJ
>
> ...
>
> > +static umode_t
> > +hwm_temp_is_visible(const struct hwm_drvdata *ddat, u32 attr)
> > +{
> > + struct i915_hwmon *hwmon = ddat->hwmon;
> > +
> > + if (attr == hwmon_temp_input && i915_mmio_reg_valid(hwmon->rg.pkg_temp))
> > + return 0444;
> > +
> > + return 0;
>
> Just a question (I'm fine with this implementation): is the style in this file
> to check for correct cases first and return an err/etc at the end?
The convention is to use switch case with err being the default, so I'd say yes.
> > +}
> > +
> > +static int
> > +hwm_temp_read(struct hwm_drvdata *ddat, u32 attr, long *val)
> > +{
> > + struct i915_hwmon *hwmon = ddat->hwmon;
> > + intel_wakeref_t wakeref;
> > + u32 reg_val;
> > +
> > + if (attr == hwmon_temp_input) {
> > + with_intel_runtime_pm(ddat->uncore->rpm, wakeref)
> > + reg_val = intel_uncore_read(ddat->uncore, hwmon->rg.pkg_temp);
> > +
> > + /* HW register value is in degrees, convert to millidegrees. */
> > + *val = REG_FIELD_GET(TEMP_MASK, reg_val) * MILLIDEGREE_PER_DEGREE;
> > + return 0;
> > + }
>
> ...because here we may drop an indentation level by doing it opposite
>
> if (x != y)
> return -E...;
>
True, but the idea is to allow more cases in the future with minimal changes.
Raag
