linux-kernel - Re: [PATCH v2] ARM: imx: allow to disable board specific PHY fixups

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Message-ID: <20200331081918.GK25745@shell.armlinux.org.uk>
Date:   Tue, 31 Mar 2020 09:19:18 +0100
From:   Russell King - ARM Linux admin <linux@...linux.org.uk>
To:     Marc Kleine-Budde <mkl@...gutronix.de>
Cc:     Florian Fainelli <f.fainelli@...il.com>,
        Andrew Lunn <andrew@...n.ch>, netdev@...r.kernel.org,
        Sascha Hauer <s.hauer@...gutronix.de>,
        linux-kernel@...r.kernel.org,
        Oleksij Rempel <o.rempel@...gutronix.de>, linux-imx@....com,
        kernel@...gutronix.de, David Jander <david@...tonic.nl>,
        Shawn Guo <shawnguo@...nel.org>,
        Fabio Estevam <festevam@...il.com>,
        linux-arm-kernel@...ts.infradead.org,
        Heiner Kallweit <hkallweit1@...il.com>
Subject: Re: [PATCH v2] ARM: imx: allow to disable board specific PHY fixups

On Tue, Mar 31, 2020 at 10:00:12AM +0200, Marc Kleine-Budde wrote:
> On 3/31/20 9:54 AM, Russell King - ARM Linux admin wrote:
> > On Tue, Mar 31, 2020 at 09:47:19AM +0200, Marc Kleine-Budde wrote:
> >> On 3/30/20 7:41 PM, Russell King - ARM Linux admin wrote:
> >>>>> arch/arm/mach-imx/mach-imx6q.c:167:		phy_register_fixup_for_uid(PHY_ID_KSZ9021, MICREL_PHY_ID_MASK,
> >>>>> arch/arm/mach-imx/mach-imx6q.c:169:		phy_register_fixup_for_uid(PHY_ID_KSZ9031, MICREL_PHY_ID_MASK,
> >>>>> arch/arm/mach-imx/mach-imx6q.c:171:		phy_register_fixup_for_uid(PHY_ID_AR8031, 0xffffffef,
> >>>>> arch/arm/mach-imx/mach-imx6q.c:173:		phy_register_fixup_for_uid(PHY_ID_AR8035, 0xffffffef,
> >>>
> >>> As far as I'm concerned, the AR8035 fixup is there with good reason.
> >>> It's not just "random" but is required to make the AR8035 usable with
> >>> the iMX6 SoCs.  Not because of a board level thing, but because it's
> >>> required for the AR8035 to be usable with an iMX6 SoC.
> >>
> >> Is this still ture, if the AR8035 is attached to a switch behind an iMX6?
> > 
> > Do you know of such a setup, or are you talking about theoretical
> > situations?
> 
> Granted, not for the AR8035, but for one of the KSZ Phys. This is why
> Oleksij started looking into this issue in the first place.

Maybe there's an easy solution to this - check whether the PHY being
fixed up is connected to the iMX6 SoC:

static bool phy_connected_to(struct phy_device *phydev,
			     const struct of_device_id *matches)
{
	struct device_node *np, *phy_np;

	for_each_matching_node(np, matches) {
		phy_np = of_parse_phandle(np, "phy-handle", 0);
		if (!phy_np)
			phy_np = of_parse_phandle(np, "phy", 0);
		if (!phy_np)
			phy_np = of_parse_phandle(np, "phy-device", 0);
		if (phy_np && phydev->mdio.dev.of_node == phy_np) {
			of_node_put(phy_np);
			of_node_put(np);
			return true;
		}
		of_node_put(phy_np);
	}
	return false;
}

static struct of_device_id imx_fec_ids[] = {
	{ .compatible = "fsl,imx6q-fec", },
	...
	{ },
};

static bool phy_connected_to_fec(struct phy_device *phydev)
{
	return phy_connected_to(phydev, imx_fec_ids);
}

and then in the fixups:

	if (!phy_connected_to_fec(phydev))
		return 0;

?

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