Re: [PATCH net-next v9 05/16] net: pcs: add Renesas MII converter driver

From: "Clément Léger" <clement.leger@bootlin.com>
To: "Russell King (Oracle)" <linux@armlinux.org.uk>
Cc: "Andrew Lunn" <andrew@lunn.ch>,
	"Vivien Didelot" <vivien.didelot@gmail.com>,
	"Florian Fainelli" <f.fainelli@gmail.com>,
	"Vladimir Oltean" <olteanv@gmail.com>,
	"David S . Miller" <davem@davemloft.net>,
	"Eric Dumazet" <edumazet@google.com>,
	"Jakub Kicinski" <kuba@kernel.org>,
	"Paolo Abeni" <pabeni@redhat.com>,
	"Rob Herring" <robh+dt@kernel.org>,
	"Krzysztof Kozlowski" <krzk+dt@kernel.org>,
	"Geert Uytterhoeven" <geert+renesas@glider.be>,
	"Magnus Damm" <magnus.damm@gmail.com>,
	"Heiner Kallweit" <hkallweit1@gmail.com>,
	"Alexandre Torgue" <alexandre.torgue@foss.st.com>,
	"Giuseppe Cavallaro" <peppe.cavallaro@st.com>,
	"Jose Abreu" <joabreu@synopsys.com>,
	"Thomas Petazzoni" <thomas.petazzoni@bootlin.com>,
	"Herve Codina" <herve.codina@bootlin.com>,
	"Miquèl Raynal" <miquel.raynal@bootlin.com>,
	"Milan Stevanovic" <milan.stevanovic@se.com>,
	"Jimmy Lalande" <jimmy.lalande@se.com>,
	"Pascal Eberhard" <pascal.eberhard@se.com>,
	linux-kernel@vger.kernel.org, devicetree@vger.kernel.org,
	linux-renesas-soc@vger.kernel.org, netdev@vger.kernel.org
Subject: Re: [PATCH net-next v9 05/16] net: pcs: add Renesas MII converter driver
Date: Tue, 28 Jun 2022 18:49:54 +0200	[thread overview]
Message-ID: <20220628184954.6757ffe4@fixe.home> (raw)
In-Reply-To: <YrsvkqBbzUvTYOeI@shell.armlinux.org.uk>

Le Tue, 28 Jun 2022 17:42:58 +0100,
"Russell King (Oracle)" <linux@armlinux.org.uk> a écrit :

> > +		break;
> > +	default:
> > +		return -EOPNOTSUPP;
> > +	}
> > +
> > +	val = FIELD_PREP(MIIC_CONVCTRL_CONV_MODE, conv_mode) |
> > +	      FIELD_PREP(MIIC_CONVCTRL_CONV_SPEED, speed);
> > +
> > +	miic_reg_rmw(miic, MIIC_CONVCTRL(port),
> > +		     MIIC_CONVCTRL_CONV_MODE | MIIC_CONVCTRL_CONV_SPEED, val);
> > +	miic_converter_enable(miic_port->miic, miic_port->port, 1);
> > +
> > +	return 0;
> > +}  
> 
> the stting of the speed here. As this function can be called as a result
> of ethtool setting the configuration while the link is up, this could
> have disasterous effects on the link. This will only happen if there is
> no PHY present and we aren't using fixed-link mode.
> 
> Therefore, I'm willing to get this pass, but I think it would be better
> if the speed was only updated if the interface setting is actually
> being changed. So:

Hi Russell,

Ok, I'll make a follow-up patch to handle that properly.

-- 
Clément Léger,
Embedded Linux and Kernel engineer at Bootlin
https://bootlin.com