On Fri, Nov 13, 2020 at 04:40:20AM +0200, Vladimir Oltean wrote:

quoted

@@ -103,6 +108,10 @@ static int ksz9477_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta)
 	if (ret)
 		goto error_return;

+	spin_lock_irqsave(&dev->ptp_clock_lock, flags);

I believe that spin_lock_irqsave is unnecessary, since there is no code
that runs in hardirq context.

The .adjtime method is in a system call context.  If all of the code
that manipulates dev->ptp_clock_time can sleep, then you can use a
mutex.  Otherwise spin_lock_irqsave is the safe choice.

Thanks,
Richard