Re: [Intel-xe] [PATCH v3 1/6] drm/xe/hwmon: Add HWMON infrastructure

["Nilawar, Badal" <badal.nilawar@intel.com>]

On 03-08-2023 04:10, Andi Shyti wrote:
> Hi Badal,
> 
> [...]
> 
>> +struct xe_hwmon_data {
>> +	struct device *hwmon_dev;
>> +	struct xe_gt *gt;
>> +	char name[12];
>> +};
>> +
>> +struct xe_hwmon {
>> +	struct xe_hwmon_data ddat;
>> +	struct mutex hwmon_lock;
>> +};
> 
> why do we need two structures here? Can we merge them?
In my previous series I mentioned its require to hold multiple hwmon 
devices.
> 
>> +static const struct hwmon_channel_info *hwmon_info[] = {
>> +	NULL
>> +};
> 
> just:
> 
>    static const struct hwmon_channel_info *hwmon_info[] = { };
> 
> would do.
sure
> 
>> +static umode_t
>> +hwmon_is_visible(const void *drvdata, enum hwmon_sensor_types type,
>> +		 u32 attr, int channel)
>> +{
>> +	struct xe_hwmon_data *ddat = (struct xe_hwmon_data *)drvdata;
>> +	int ret;
>> +
>> +	xe_device_mem_access_get(gt_to_xe(ddat->gt));
>> +
>> +	switch (type) {
>> +	default:
>> +		ret = 0;
>> +		break;
>> +	}
>> +
>> +	xe_device_mem_access_put(gt_to_xe(ddat->gt));
>> +
>> +	return ret;
> 
> OK... we are forced to go through the switch and initialize ret.
> Would be nicer to initialize ret to '0'... but it's not
> important, feel free to ignore this comment if the compiler
> doesn't complain.
> 
>> +}
> 
> [...]
> 
>> +	/*  hwmon_dev points to device hwmon<i> */
>> +	hwmon_dev = devm_hwmon_device_register_with_info(dev, ddat->name,
>> +							 ddat,
>> +							 &hwmon_chip_info,
>> +							 NULL);
>> +	if (IS_ERR(hwmon_dev)) {
>> +		drm_warn(&xe->drm, "Fail to register xe hwmon, Err:%ld\n", PTR_ERR(hwmon_dev));
> 
> I think this is better:
> 
>     drm_warn(&xe->drm, "Fail to register xe hwmon (%pe)\n", hwmon_dev);
Sure
> 
>> +		xe->hwmon = NULL;
>> +		return;
>> +	}
>> +
>> +	ddat->hwmon_dev = hwmon_dev;
>> +}
>> +
>> +void xe_hwmon_unregister(struct xe_device *xe)
>> +{
>> +	xe->hwmon = NULL;
> 
> I think this is not necessary. Will xe check for hwmon at some
> point?
Yes this not needed as we are using devm_hwmon* function to register 
hwmon but in i915 patches this was suggested for sanity. I will remove 
this function.

Regards,
Badal
> 
> Andi
> 
>> +}