netdev - Re: [PATCH net-next 2/3] net: dsa: mv88e6xxx: replace ATU violation prints with trace points

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Message-ID: <20221208144901.tgdhp73n7g5uh7qj@skbuf>
Date:   Thu, 8 Dec 2022 16:49:01 +0200
From:   Vladimir Oltean <vladimir.oltean@....com>
To:     Saeed Mahameed <saeed@...nel.org>
Cc:     netdev@...r.kernel.org, Andrew Lunn <andrew@...n.ch>,
        Florian Fainelli <f.fainelli@...il.com>,
        "David S. Miller" <davem@...emloft.net>,
        Eric Dumazet <edumazet@...gle.com>,
        Jakub Kicinski <kuba@...nel.org>,
        Paolo Abeni <pabeni@...hat.com>,
        "Hans J. Schultz" <netdev@...io-technology.com>
Subject: Re: [PATCH net-next 2/3] net: dsa: mv88e6xxx: replace ATU violation
 prints with trace points

On Wed, Dec 07, 2022 at 04:14:16PM -0800, Saeed Mahameed wrote:
> > 	if (val & MV88E6XXX_G1_ATU_OP_AGE_OUT_VIOLATION) {
> > -		dev_err_ratelimited(chip->dev,
> > -				    "ATU age out violation for %pM fid %u\n",
> > -				    entry.mac, fid);
> > +		trace_mv88e6xxx_atu_age_out_violation(chip->dev, spid,
> > +						      entry.mac, fid);
> 
> no stats here? tracepoints are disabled by default and this event will go
> unnoticed, users usually monitor light weight indicators such as stats, then
> turn on tracepoints to see what's actually happening..

I believe that the ATU age out violation handler is dead code currently.
The driver does not enable the MV88E6XXX_PORT_ASSOC_VECTOR_INT_AGE_OUT bit
(interrupt on age out).

I just converted the existing debugging prints to trace points. Open to
more suggestions, but I believe that if I introduce a counter, it would
always return 0.