Re: [PATCH net-next v2] ptp: add Alibaba CIPU PTP clock driver

[Wen Gu <guwen@linux.alibaba.com>]

On 2025/6/27 18:59, Vadim Fedorenko wrote:
> On 27/06/2025 08:57, Andrew Lunn wrote:
> 
>>> +static int ptp_cipu_enable(struct ptp_clock_info *info,
>>> +               struct ptp_clock_request *request, int on)
>>> +{
>>> +    return -EOPNOTSUPP;
>>> +}
>>> +
>>> +static int ptp_cipu_settime(struct ptp_clock_info *p,
>>> +                const struct timespec64 *ts)
>>> +{
>>> +    return -EOPNOTSUPP;
>>> +}
>>> +
>>> +static int ptp_cipu_adjfine(struct ptp_clock_info *ptp, long scaled_ppm)
>>> +{
>>> +    return -EOPNOTSUPP;
>>> +}
>>> +
>>> +static int ptp_cipu_adjtime(struct ptp_clock_info *ptp, s64 delta)
>>> +{
>>> +    return -EOPNOTSUPP;
>>> +}
>>
>> I've not looked at the core. Are these actually required? Or if they
>> are missing, does the core default to -EOPNOTSUPP?
>>
> 
> I was going to say that these are not needed because posix clocks do
> check if callbacks are assigned and return -EOPNOTSUPP if they are not.
> That's why ptp_clock_* functions do call these callbacks without checks.

Hi Vadim, do you mean posix clock functions like this:

e.g. posix-clock.c:

static int pc_clock_settime(clockid_t id, const struct timespec64 *ts)
{
<...>
	if (cd.clk->ops.clock_settime)
		err = cd.clk->ops.clock_settime(cd.clk, ts);
	else
		err = -EOPNOTSUPP;
<...>
}

In ptp_clock.c, ops.clock_settime() is assigned to ptp_clock_settime(),
and it will call ptp->info->settime64() without checks. So I think these
'return -EOPNOTSUPP' functions are needed. Did I miss something?

Thanks!