Re: [PATCH RFC russell-king 3/4] net: phy: marvell10g: change MACTYPE according to phydev->interface - Russell King

From: Russell King - ARM Linux admin <linux@armlinux.org.uk>
To: "Marek Behún" <marek.behun@nic.cz>
Cc: Andrew Lunn <andrew@lunn.ch>,
	Maxime Chevallier <maxime.chevallier@bootlin.com>,
	Baruch Siach <baruch@tkos.co.il>, Chris Healy <cphealy@gmail.com>,
	Florian Fainelli <f.fainelli@gmail.com>,
	netdev@vger.kernel.org
Subject: Re: [PATCH RFC russell-king 3/4] net: phy: marvell10g: change MACTYPE according to phydev->interface
Date: Tue, 11 Aug 2020 16:21:44 +0100	[thread overview]
Message-ID: <20200811152144.GN1551@shell.armlinux.org.uk> (raw)
In-Reply-To: <20200810220645.19326-4-marek.behun@nic.cz>

On Tue, Aug 11, 2020 at 12:06:44AM +0200, Marek Behún wrote:
> RollBall SFPs contain Marvell 88X3310 PHY, but they have configuration
> pins strapped so that MACTYPE is configured in XFI with Rate Matching
> mode.
> 
> When these SFPs are inserted into a device which only supports lower
> speeds on host interface, we need to configure the MACTYPE to a mode
> in which the H unit changes SerDes speed according to speed on the
> copper interface. I chose to use the
> 10GBASE-R/5GBASE-R/2500BASE-X/SGMII with AN mode.

We actually need to have more inteligence in the driver, since we
actually assume that it is in the 10GBASE-R/5GBASE-R/2500BASE-X/SGMII
mode without really checking.

Note that there are differences in the way the mactype field is
interpreted depending on exactly what chip we have.  For example,
3310 and 3340 are different.  That said, I've not heard of anyone
using the 3340 yet.

-- 
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
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