[PATCH] net: stmmac: Change the busy-wait loops timing

[Simon Horman]

On Fri, Jun 06, 2025 at 12:19:49PM +0200, Bartlomiej Dziag wrote:
> After writing a new value to the PTP_TAR or PTP_STSUR registers,
> the driver waits for the addend/adjust operations to complete.
> Sometimes, the first check operation fails, resulting in
> a 10 milliseconds busy-loop before performing the next check.
> Since updating the registers takes much less than 10 milliseconds,
> the kernel gets stuck unnecessarily. This may increase the CPU usage.
> Fix that with changing the busy-loop interval to 5 microseconds.
> The registers will be checked more often.

Hi Bartlomiej,

I am curious.

Does it always take much less than 10ms, or is that usually so.
If it is the former, then do we need to wait for in the order of
10000 x 5us = 50ms before giving up?

> 
> Signed-off-by: Bartlomiej Dziag <bartlomiejdziag at gmail.com>

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