From mboxrd@z Thu Jan  1 00:00:00 1970
From: Andrew Lunn <andrew@lunn.ch>
Subject: Re: [RFC PATCH 04/10] net: dsa: mv88e6xxx: expose switch time as a
 PTP hardware clock
Date: Fri, 9 Feb 2018 22:04:59 +0100
Message-ID: <20180209210459.GC2079@lunn.ch>
References: <1517694016-6692-1-git-send-email-andrew@lunn.ch>
 <1517694016-6692-5-git-send-email-andrew@lunn.ch>
 <20180209203336.fqkuliaqmonl67jg@localhost>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Cc: netdev <netdev@vger.kernel.org>,
        Florian Fainelli <f.fainelli@gmail.com>,
        Vivien Didelot <vivien.didelot@savoirfairelinux.com>,
        sean.wang@mediatek.com, Woojung.Huh@microchip.com,
        john@phrozen.org, jbe@pengutronix.de,
        Brandon Streiff <brandon.streiff@ni.com>
To: Richard Cochran <richardcochran@gmail.com>
Return-path: <netdev-owner@vger.kernel.org>
Received: from vps0.lunn.ch ([185.16.172.187]:49967 "EHLO vps0.lunn.ch"
        rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP
        id S1750993AbeBIVFE (ORCPT <rfc822;netdev@vger.kernel.org>);
        Fri, 9 Feb 2018 16:05:04 -0500
Content-Disposition: inline
In-Reply-To: <20180209203336.fqkuliaqmonl67jg@localhost>
Sender: netdev-owner@vger.kernel.org
List-ID: <netdev.vger.kernel.org>

On Fri, Feb 09, 2018 at 12:33:36PM -0800, Richard Cochran wrote:
> On Sat, Feb 03, 2018 at 10:40:08PM +0100, Andrew Lunn wrote:
> > +static int mv88e6xxx_ptp_adjfine(struct ptp_clock_info *ptp, long scaled_ppm)
> > +{
> > +	struct mv88e6xxx_chip *chip = ptp_to_chip(ptp);
> > +	int neg_adj = 0;
> > +	u32 diff, mult;
> > +	u64 adj;
> > +
> > +	if (scaled_ppm < 0) {
> > +		neg_adj = 1;
> > +		scaled_ppm = -scaled_ppm;
> > +	}
> > +	mult = CC_MULT;
> > +	adj = scaled_ppm * CC_MULT_NUM;
>               ^^^^^^^^^^^^^^^^^^^^^^^^
> This easily overflows on 32 bit platforms.  My bad.  Fix below...

Hi Richard

Thanks, i will squash the fix in for the next version.

	Andrew