Re: net: dsa: microchip: issues when using PTP between KSZ9567 devices

[Andrew Lunn <andrew@lunn.ch>]

> Issue 3
> -------
> When performing the port_hwtstamp_set operation, ptp_schedule_worker()
> will be called if hardware timestamoing is enabled on any of the ports.
> When using multiple ports for PTP, port_hwtstamp_set is executed for
> each port. When called for the first time ptp_schedule_worker() returns
> 0. On subsequent calls it returns 1, indicating the worker is already
> scheduled. Currently the ksz_ptp module treats 1 as an error and fails
> to complete the port_hwtstamp_set operation, thus leaving the
> timestamping configuration for those ports unchanged.
> 
> (note that the documentation of ptp_schedule_worker refers you to
> kthread_queue_delayed_work rather than documenting the return values,
> but kthread_queue_delayed_work returns a bool, not an int)
> 
> I fixed this issue by
> 
> diff --git a/drivers/net/dsa/microchip/ksz_ptp.c
> b/drivers/net/dsa/microchip/ksz_ptp.c
> index 4e22a695a64c..7ef5fac69657 100644
> --- a/drivers/net/dsa/microchip/ksz_ptp.c
> +++ b/drivers/net/dsa/microchip/ksz_ptp.c
> @@ -266,7 +266,6 @@ static int ksz_ptp_enable_mode(struct ksz_device *dev)
>         struct ksz_port *prt;
>         struct dsa_port *dp;
>         bool tag_en = false;
> -       int ret;
> 
>         dsa_switch_for_each_user_port(dp, dev->ds) {
>                 prt = &dev->ports[dp->index];
> @@ -277,9 +276,7 @@ static int ksz_ptp_enable_mode(struct ksz_device *dev)
>         }
> 
>         if (tag_en) {
> -               ret = ptp_schedule_worker(ptp_data->clock, 0);
> -               if (ret)
> -                       return ret;
> +               ptp_schedule_worker(ptp_data->clock, 0);

This looks correct. Please could you submit a formal patch?

https://docs.kernel.org/process/submitting-patches.html
https://www.kernel.org/doc/html/latest/process/maintainer-netdev.html#netdev-faq

	Andrew