Re: [PATCH net-next v5 2/2] net: phy: broadcom: Add PTP support for some Broadcom PHYs.

From: Richard Cochran <richardcochran@gmail.com>
To: Jonathan Lemon <jonathan.lemon@gmail.com>
Cc: netdev@vger.kernel.org, f.fainelli@gmail.com, andrew@lunn.ch,
	hkallweit1@gmail.com, linux@armlinux.org.uk,
	bcm-kernel-feedback-list@broadcom.com, kernel-team@fb.com,
	davem@davemloft.net, kuba@kernel.org, pabeni@redhat.com,
	edumazet@google.com
Subject: Re: [PATCH net-next v5 2/2] net: phy: broadcom: Add PTP support for some Broadcom PHYs.
Date: Sat, 28 May 2022 17:34:47 -0700	[thread overview]
Message-ID: <20220529003447.GA32026@hoboy.vegasvil.org> (raw)
In-Reply-To: <20220518223935.2312426-3-jonathan.lemon@gmail.com>

On Wed, May 18, 2022 at 03:39:35PM -0700, Jonathan Lemon wrote:

> +static int bcm_ptp_adjtime_locked(struct bcm_ptp_private *priv,
> +				  s64 delta_ns)
> +{
> +	struct timespec64 ts;
> +	int err;
> +
> +	err = bcm_ptp_gettime_locked(priv, &ts, NULL);
> +	if (!err) {
> +		set_normalized_timespec64(&ts, ts.tv_sec,
> +					  ts.tv_nsec + delta_ns);

This also takes a LONG time when delta is large...

> +		err = bcm_ptp_settime_locked(priv, &ts);
> +	}
> +	return err;
> +}

Try this instead:

	s64 ns;

	err = bcm_ptp_gettime_locked(priv, &ts, NULL);
	if (err) {
		return err;
	}
	ns = timespec64_to_ns(&ts);		
	ns += delta_ns;
	ts = ns_to_timespec64(ns);
	err = bcm_ptp_settime_locked(priv, &ts);

	return err;

Thanks,
Richard