Re: [PATCH v2 2/2] phy: nxp-c45-tja11xx: read the tx timestamp without lock

From: Richard Cochran
Date: Thu Dec 23 2021 - 15:24:24 EST


On Wed, Dec 22, 2021 at 11:34:53PM +0200, Radu Pirea (NXP OSS) wrote:
> Reading the tx timestamps can be done in parallel with adjusting the LTC
> value.
>
> Calls to nxp_c45_get_hwtxts() are always serialised. If the phy
> interrupt is enabled, .do_aux_work() will not call nxp_c45_get_hwtxts.

Reviewing the code, I see what you mean. However, the serialization
is completely non-obvious, and future changes to the driver could
easily spoil the implicit serialization. Given that the mutex is not
highly contended, I suggest dropping this patch in order to
future-proof the driver.

Thanks,
Richard