> -----Original Message-----
> From: Miroslav Lichvar <mlich...@redhat.com>
> Sent: Thursday, March 10, 2022 3:23 AM
> To: linuxptp-devel@lists.sourceforge.net
> Subject: [Linuxptp-devel] [PATCH] phc2sys: Don't exit when reading of PHC
> fails.
>
> Reading of the PHC can occasionally fail with some drivers, e.g. the ice
> driver returns -EBUSY when it fails to get a lock. Change do_loop() to
> ignore the error instead of exiting.
>
> Signed-off-by: Miroslav Lichvar <mlich...@redhat.com>
> ---
Yep. Thanks for fixing this. I'd like to clarify why ice does sometimes return
-EBUSY for reviewers on this list.
The ice hardware has a semaphore to protect accesses to the clock register.
Multiple functions might access the clock at the same time. The semaphore
prevents this. If we fail to acquire the semaphore in a short time, we give up
on the gettime function and exit with -EBUSY.
Does the inner call log a debug message? if not perhaps we might want to add
such a debug message to this as well?
Thanks,
Jake
> phc2sys.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/phc2sys.c b/phc2sys.c
> index 15dd689..281ec9d 100644
> --- a/phc2sys.c
> +++ b/phc2sys.c
> @@ -730,7 +730,7 @@ static int do_loop(struct phc2sys_private *priv)
> priv->master->sysoff_method,
> priv->phc_readings,
> &offset, &ts, &delay) < 0)
> - return -1;
> + continue;
> } else if (priv->master->clkid == CLOCK_REALTIME &&
> clock->sysoff_method >= 0) {
> /* use reversed sysoff */
> @@ -738,7 +738,7 @@ static int do_loop(struct phc2sys_private *priv)
> clock->sysoff_method,
> priv->phc_readings,
> &offset, &ts, &delay) < 0)
> - return -1;
> + continue;
> offset = -offset;
> ts += offset;
> } else {
> @@ -747,7 +747,7 @@ static int do_loop(struct phc2sys_private *priv)
> clock->clkid,
> priv->phc_readings,
> &offset, &ts, &delay))
> - return -1;
> + continue;
> }
> update_clock(priv, clock, offset, ts, delay);
> }
> --
> 2.35.1
>
>
>
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