Re: [PATCH net-next 2/3] dpll: add actual frequency monitoring callback ops

[Ivan Vecera <ivecera@redhat.com>]

On 3/26/26 12:21 PM, Vadim Fedorenko wrote:
> On 25/03/2026 19:39, Ivan Vecera wrote:
> 
>> +static int dpll_msg_add_actual_freq(struct sk_buff *msg, struct 
>> dpll_pin *pin,
>> +                    struct dpll_pin_ref *ref,
>> +                    struct netlink_ext_ack *extack)
>> +{
>> +    const struct dpll_device_ops *dev_ops = dpll_device_ops(ref->dpll);
>> +    const struct dpll_pin_ops *ops = dpll_pin_ops(ref);
>> +    struct dpll_device *dpll = ref->dpll;
>> +    enum dpll_feature_state state;
>> +    u64 actual_freq;
>> +    int ret;
>> +
>> +    if (!ops->actual_freq_get)
>> +        return 0;
>> +    if (dev_ops->freq_monitor_get) {
>> +        ret = dev_ops->freq_monitor_get(dpll, dpll_priv(dpll),
>> +                        &state, extack);
>> +        if (ret)
>> +            return ret;
>> +        if (state == DPLL_FEATURE_STATE_DISABLE)
>> +            return 0;
> 
> I think we have to signal back to user that frequency monitoring is
> disabled via extack.

Hi Vadim,

This would break pin-get operation... Do or dump pin-get operation would
fail with this extack message.

Here we can check if the freq-monitoring is enabled and conditionally
call actual_freq_get() or measured_freq_get()

-or-

Call this callback unconditionally and check for return code and if a
driver returns e.g. -ENODATA then skip nla_put_64bit() but return
success.

WDYT?

Thanks,
Ivan