Re: [PATCH v2 1/1] net: fec: ptp: avoid register access when ipg clock is disabled

Richard Cochran
2021-02-26T15:24:27Z

On Thu, Feb 25, 2021 at 10:15:16PM +0100, Heiko Thiery wrote:
> When accessing the timecounter register on an i.MX8MQ the kernel hangs.
> This is only the case when the interface is down. This can be reproduced
> by reading with 'phc_ctrl eth0 get'.
>
> Like described in the change in 91c0d987a9788dcc5fe26baafd73bf9242b68900
> the igp clock is disabled when the interface is down and leads to a
> system hang.
>
> So we check if the ptp clock status before reading the timecounter
> register.
>
> Signed-off-by: Heiko Thiery <heiko.thiery@gmail.com>
> ---
> v2:
> - add mutex (thanks to Richard)
>
> v3:
> I did a mistake and did not test properly
> - add parenteses
> - fix the used variable

Acked-by: Richard Cochran <richardcochran@gmail.com>