Hi Richard,
> -----Original Message-----
> From: Richard Cochran <richardcochran@xxxxxxxxx>
> Sent: 2021年6月18日 2:28
> To: Y.b. Lu <yangbo.lu@xxxxxxx>
> Cc: netdev@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx;
> linux-kselftest@xxxxxxxxxxxxxxx; mptcp@xxxxxxxxxxxxxxx; David S . Miller
> <davem@xxxxxxxxxxxxx>; Jakub Kicinski <kuba@xxxxxxxxxx>; Mat Martineau
> <mathew.j.martineau@xxxxxxxxxxxxxxx>; Matthieu Baerts
> <matthieu.baerts@xxxxxxxxxxxx>; Shuah Khan <shuah@xxxxxxxxxx>; Michal
> Kubecek <mkubecek@xxxxxxx>; Florian Fainelli <f.fainelli@xxxxxxxxx>;
> Andrew Lunn <andrew@xxxxxxx>; Rui Sousa <rui.sousa@xxxxxxx>; Sebastien
> Laveze <sebastien.laveze@xxxxxxx>
> Subject: Re: [net-next, v3, 02/10] ptp: support ptp physical/virtual clocks
> conversion
>
> On Tue, Jun 15, 2021 at 05:45:09PM +0800, Yangbo Lu wrote:
>
> > diff --git a/drivers/ptp/ptp_private.h b/drivers/ptp/ptp_private.h
> > index 3f388d63904c..6949afc9d733 100644
> > --- a/drivers/ptp/ptp_private.h
> > +++ b/drivers/ptp/ptp_private.h
> > @@ -46,6 +46,9 @@ struct ptp_clock {
> > const struct attribute_group *pin_attr_groups[2];
> > struct kthread_worker *kworker;
> > struct kthread_delayed_work aux_work;
> > + u8 n_vclocks;
>
> Hm, type is u8, but ...
>
> > + struct mutex n_vclocks_mux; /* protect concurrent n_vclocks access */
> > + bool vclock_flag;
> > };
> >
>
> > #define info_to_vclock(d) container_of((d), struct ptp_vclock, info)
> > diff --git a/include/uapi/linux/ptp_clock.h
> > b/include/uapi/linux/ptp_clock.h index 1d108d597f66..4b933dc1b81b
> > 100644
> > --- a/include/uapi/linux/ptp_clock.h
> > +++ b/include/uapi/linux/ptp_clock.h
> > @@ -69,6 +69,11 @@
> > */
> > #define PTP_PEROUT_V1_VALID_FLAGS (0)
> >
> > +/*
> > + * Max number of PTP virtual clocks per PTP physical clock */
> > +#define PTP_MAX_VCLOCKS 20
>
> Only 20 clocks are allowed? Why?
Initially I think vclock can be used for ptp multiple domains synchronization. Since the PTP domainValue is u8, u8 vclock number is large enough.
This is not a good idea to hard-code a PTP_MAX_VCLOCKS value. But it looks a little crazy to create numbers of vclocks via one command (echo n > /sys/class/ptp/ptp0/n_vclocks).
Maybe a typo creates hundreds of vclocks we don’t need.
Do you think we should be care about setting a limitation of vclock number? Any suggestion for implementation?
Thanks.
>
> Thanks,
> Richard
