Re: [PATCH 3/3] phy: nxp-c45-tja11xx: read the tx timestamp without lock

From: Radu Nicolae Pirea (NXP OSS)
Date: Wed Dec 22 2021 - 03:19:39 EST


On Mon, 2021-12-20 at 16:10 +0100, Andrew Lunn wrote:
> On Mon, Dec 20, 2021 at 02:08:59PM +0200, Radu Pirea (NXP OSS) wrote:
> > The tx timestamps are read from only one place in interrupt or
> > polling
> > mode. Locking the mutex is useless.
>
> You cannot take a mutex in an interrupt handler. So your description
> is probably not accurate.
Actually this is the second issue.
I will improve the description.
>
> Is it safe for other ptp operations to be performed in parallel with
> reading the TX timestamp? _nxp_c45_ptp_settime64()?
Yes, it's safe. The purpose of the mutex is to protect the access to
LTC(PTP counter).
>
>         Andrew