Date:   Thu, 25 Nov 2021 19:05:18 +0200
From:   Vladimir Oltean <olteanv@gmail.com>
To:     Richard Cochran <richardcochran@gmail.com>
Cc:     Martin Kaistra <martin.kaistra@linutronix.de>,
        Florian Fainelli <f.fainelli@gmail.com>,
        Andrew Lunn <andrew@lunn.ch>,
        Vivien Didelot <vivien.didelot@gmail.com>,
        Kurt Kanzenbach <kurt@linutronix.de>,
        "David S. Miller" <davem@davemloft.net>,
        Jakub Kicinski <kuba@kernel.org>,
        John Stultz <john.stultz@linaro.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Stephen Boyd <sboyd@kernel.org>,
        Russell King <linux@armlinux.org.uk>,
        Marc Kleine-Budde <mkl@pengutronix.de>,
        linux-kernel@vger.kernel.org, netdev@vger.kernel.org
Subject: Re: [PATCH 7/7] net: dsa: b53: Expose PTP timestamping ioctls to
 userspace
Message-ID: <20211125170518.socgptqrhrds2vl3@skbuf>
References: <20211104133204.19757-8-martin.kaistra@linutronix.de>
 <20211104174251.GB32548@hoboy.vegasvil.org>
 <ba543ae4-3a71-13fe-fa82-600ac37eaf5a@linutronix.de>
 <20211105141319.GA16456@hoboy.vegasvil.org>
 <20211105142833.nv56zd5bqrkyjepd@skbuf>
 <20211106001804.GA24062@hoboy.vegasvil.org>
 <20211106003606.qvfkitgyzoutznlw@skbuf>
 <20211107140534.GB18693@hoboy.vegasvil.org>
 <20211107142703.tid4l4onr6y2gxic@skbuf>
 <20211108144824.GD7170@hoboy.vegasvil.org>
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On Mon, Nov 08, 2021 at 06:48:24AM -0800, Richard Cochran wrote:
> On Sun, Nov 07, 2021 at 04:27:03PM +0200, Vladimir Oltean wrote:
> > On Sun, Nov 07, 2021 at 06:05:34AM -0800, Richard Cochran wrote:
> > >         switch (cfg.rx_filter) {
> > >         case HWTSTAMP_FILTER_NONE:
> > >                 break;
> > >         case HWTSTAMP_FILTER_ALL:
> > >         case HWTSTAMP_FILTER_SOME:
> > >         case HWTSTAMP_FILTER_PTP_V1_L4_EVENT:
> > >         case HWTSTAMP_FILTER_PTP_V1_L4_SYNC:
> > >         case HWTSTAMP_FILTER_PTP_V1_L4_DELAY_REQ:
> > >         case HWTSTAMP_FILTER_NTP_ALL:
> > >         case HWTSTAMP_FILTER_PTP_V2_L4_EVENT:
> > >         case HWTSTAMP_FILTER_PTP_V2_L4_SYNC:
> > >         case HWTSTAMP_FILTER_PTP_V2_L4_DELAY_REQ:
> > >         case HWTSTAMP_FILTER_PTP_V2_L2_EVENT:
> > >         case HWTSTAMP_FILTER_PTP_V2_L2_SYNC:
> > >         case HWTSTAMP_FILTER_PTP_V2_L2_DELAY_REQ:
> > >         case HWTSTAMP_FILTER_PTP_V2_EVENT:
> > >         case HWTSTAMP_FILTER_PTP_V2_SYNC:
> > >         case HWTSTAMP_FILTER_PTP_V2_DELAY_REQ:
> > >                 cfg.rx_filter = HWTSTAMP_FILTER_PTP_V2_EVENT;
> > >                 break;
> > >         default:
> > >                 mutex_unlock(&ocelot->ptp_lock);
> > >                 return -ERANGE;
> > >         }
> > > 
> > > That is essentially an upgrade to HWTSTAMP_FILTER_PTP_V2_EVENT.  The
> > > change from ALL to HWTSTAMP_FILTER_PTP_V2_EVENT is probably a simple
> > > oversight, and the driver can be easily fixed.
> > > 
> > > Thanks,
> > > Richard
> > 
> > It's essentially the same pattern as what Martin is introducing for b53.
> 
> Uh, no it isn't.  The present patch has:
> 
> +       case HWTSTAMP_FILTER_PTP_V2_L2_EVENT:
> +       case HWTSTAMP_FILTER_PTP_V2_L2_SYNC:
> +       case HWTSTAMP_FILTER_PTP_V2_L2_DELAY_REQ:
> +       case HWTSTAMP_FILTER_PTP_V2_EVENT:
> +       case HWTSTAMP_FILTER_PTP_V2_SYNC:
> +       case HWTSTAMP_FILTER_PTP_V2_DELAY_REQ:
> +       case HWTSTAMP_FILTER_ALL:
> +               config->rx_filter = HWTSTAMP_FILTER_PTP_V2_L2_EVENT;
> 
> There is an important difference between
> HWTSTAMP_FILTER_PTP_V2_L2_EVENT and HWTSTAMP_FILTER_PTP_V2_EVENT
> 
> Notice the "L2" in there.

Richard, when the request is PTP_V2_EVENT and the response is
PTP_V2_L2_EVENT, is that an upgrade or a downgrade? PTP_V2_EVENT also
includes PTP_V2_L4_EVENT.