Subject: Re: [PATCH net v2 1/1] net: fec: fix the PTP periodic output sysfs interface

From: Jakub Kicinski <[email-masked]>
Date: Mon, 23 Mar 2026 17:28:42 -0700

On Mon, 23 Mar 2026 12:54:46 +0000 Wei Fang wrote:
> > When the PPS channel configuration was implemented, the number of
> > supported periodic outputs (`n_per_out`) was left at 1.
> > 
> > This prohibits using channels 1..3 from the sysfs interface, since
> > period_store() rejects channel numbers greater than `n_per_out`.
> > 
> > Fix by increasing `n_per_out` to the number of channels supported
> > by the hardware.
> > 
> > Fixes: 566c2d83887f ("net: fec: make PPS channel configurable")
> > Signed-off-by: Buday Csaba <[email-masked]>
> > ---
> >  drivers/net/ethernet/freescale/fec_ptp.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/drivers/net/ethernet/freescale/fec_ptp.c
> > b/drivers/net/ethernet/freescale/fec_ptp.c
> > index 4b7bad9a485d..1a7aa280e7f6 100644
> > --- a/drivers/net/ethernet/freescale/fec_ptp.c
> > +++ b/drivers/net/ethernet/freescale/fec_ptp.c
> > @@ -756,7 +756,7 @@ void fec_ptp_init(struct platform_device *pdev, int
> > irq_idx)
> >  	fep->ptp_caps.max_adj = 250000000;
> >  	fep->ptp_caps.n_alarm = 0;
> >  	fep->ptp_caps.n_ext_ts = 0;
> > -	fep->ptp_caps.n_per_out = 1;
> > +	fep->ptp_caps.n_per_out = 4;
> >  	fep->ptp_caps.n_pins = 0;
> >  	fep->ptp_caps.pps = 1;
> >  	fep->ptp_caps.adjfine = fec_ptp_adjfine;
> > 
> Reviewed-by: Wei Fang <[email-masked]>

I don't understand why you think that we should be exposing 4 channels
to the user when they can only use one. And have the user guess which
one should be programmed. Please explain (and Buday will have to update
the commit message), to me v1 looked like a much better fix.
-- 
pw-bot: cr