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Date:   Tue, 25 Apr 2023 14:18:08 +0200
From:   Andrew Lunn <andrew@lunn.ch>
To:     Siddharth Vadapalli <s-vadapalli@ti.com>
Cc:     hkallweit1@gmail.com, linux@armlinux.org.uk, davem@davemloft.net,
        edumazet@google.com, kuba@kernel.org, pabeni@redhat.com,
        netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org, srk@ti.com
Subject: Re: [RFC PATCH 2/2] net: phy: dp83869: fix mii mode when rgmii strap
 cfg is used
Message-ID: <cbbedaab-b2bf-4a37-88ed-c1a8211920e9@lunn.ch>
References: <20230425054429.3956535-1-s-vadapalli@ti.com>
 <20230425054429.3956535-3-s-vadapalli@ti.com>
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On Tue, Apr 25, 2023 at 11:14:29AM +0530, Siddharth Vadapalli wrote:
> From: Grygorii Strashko <grygorii.strashko@ti.com>
> 
> The DP83869 PHY on TI's k3-am642-evm supports both MII and RGMII
> interfaces and is configured by default to use RGMII interface (strap).
> However, the board design allows switching dynamically to MII interface
> for testing purposes by applying different set of pinmuxes.

Only for testing? So nobody should actually design a board to use MII
and use software to change the interface from RGMII to MII?

This does not seem to be a fix, it is a new feature. So please submit
to net-next, in two weeks time when it opens again.

> @@ -692,8 +692,11 @@ static int dp83869_configure_mode(struct phy_device *phydev,
>  	/* Below init sequence for each operational mode is defined in
>  	 * section 9.4.8 of the datasheet.
>  	 */
> +	phy_ctrl_val = dp83869->mode;
> +	if (phydev->interface == PHY_INTERFACE_MODE_MII)
> +		phy_ctrl_val |= DP83869_OP_MODE_MII;

Should there be some validation here with dp83869->mode?

DP83869_RGMII_COPPER_ETHERNET, DP83869_RGMII_SGMII_BRIDGE etc don't
make sense if MII is being used. DP83869_100M_MEDIA_CONVERT and maybe
DP83869_RGMII_100_BASE seem to be the only valid modes with MII?

	Andrew