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

[Richard Cochran]

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@xxxxxxxxx>
> ---
> 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@xxxxxxxxx>