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

[Vadim Fedorenko <vadim.fedorenko@linux.dev>]

On 30/03/2026 09:52, Ivan Vecera wrote:
> On 3/26/26 6:48 PM, Ivan Vecera wrote:
>> 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()

Let's make it this way, we don't want to waste even small amount of
resources for useless call.

>>
>> -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?
> 
> Vadim?

Sorry, was AFK this Friday/weekend