of_mdio: add new DT property 'managed' to specify the PHY management type (4cba5c21) · Commits · 戴 / test

Currently the PHY management type is selected by the MAC driver arbitrary. The decision is based on the presence of the "fixed-link" node and on a will of the driver's authors. This caused a regression recently, when mvneta driver suddenly started to use the in-band status for auto-negotiation on fixed links. It appears the auto-negotiation may not work when expected by the MAC driver. Sebastien Rannou explains: << Yes, I confirm that my HW does not generate an in-band status. AFAIK, it's a PHY that aggregates 4xSGMIIs to 1xQSGMII ; the MAC side of the PHY (with inband status) is connected to the switch through QSGMII, and in this context we are on the media side of the PHY. >> https://lkml.org/lkml/2015/7/10/206 This patch introduces the new string property 'managed' that allows the user to set the management type explicitly. The supported values are: "auto" - default. Uses either MDIO or nothing, depending on the presence of the fixed-link node "in-band-status" - use in-band status Signed-off-by:

Stas Sergeev <stsp@users.sourceforge.net> CC: Rob Herring <robh+dt@kernel.org> CC: Pawel Moll <pawel.moll@arm.com> CC: Mark Rutland <mark.rutland@arm.com> CC: Ian Campbell <ijc+devicetree@hellion.org.uk> CC: Kumar Gala <galak@codeaurora.org> CC: Florian Fainelli <f.fainelli@gmail.com> CC: Grant Likely <grant.likely@linaro.org> CC: devicetree@vger.kernel.org CC: linux-kernel@vger.kernel.org CC: netdev@vger.kernel.org Signed-off-by:

David S. Miller <davem@davemloft.net>

Documentation/devicetree/bindings/net/ethernet.txt

+4 −0

Original line number	Diff line number	Diff line
		@@ -25,7 +25,11 @@ The following properties are common to the Ethernet controllers:
		flow control thresholds.
		- tx-fifo-depth: the size of the controller's transmit fifo in bytes. This
		is used for components that can have configurable fifo sizes.
		- managed: string, specifies the PHY management type. Supported values are:
		"auto", "in-band-status". "auto" is the default, it usess MDIO for
		management if fixed-link is not specified.

		Child nodes of the Ethernet controller are typically the individual PHY devices
		connected via the MDIO bus (sometimes the MDIO bus controller is separate).
		They are described in the phy.txt file in this same directory.
		For non-MDIO PHY management see fixed-link.txt.

drivers/of/of_mdio.c

+17 −2

Original line number	Diff line number	Diff line
		@@ -266,7 +266,8 @@ EXPORT_SYMBOL(of_phy_attach);
		bool of_phy_is_fixed_link(struct device_node *np)
		{
		struct device_node *dn;
		int len;
		int len, err;
		const char *managed;

		/* New binding */
		dn = of_get_child_by_name(np, "fixed-link");
		@@ -275,6 +276,10 @@ bool of_phy_is_fixed_link(struct device_node *np)
		return true;
		}

		err = of_property_read_string(np, "managed", &managed);
		if (err == 0 && strcmp(managed, "auto") != 0)
		return true;

		/* Old binding */
		if (of_get_property(np, "fixed-link", &len) &&
		len == (5 * sizeof(__be32)))
		@@ -289,8 +294,18 @@ int of_phy_register_fixed_link(struct device_node *np)
		struct fixed_phy_status status = {};
		struct device_node *fixed_link_node;
		const __be32 *fixed_link_prop;
		int len;
		int len, err;
		struct phy_device *phy;
		const char *managed;

		err = of_property_read_string(np, "managed", &managed);
		if (err == 0) {
		if (strcmp(managed, "in-band-status") == 0) {
		/* status is zeroed, namely its .link member */
		phy = fixed_phy_register(PHY_POLL, &status, np);
		return IS_ERR(phy) ? PTR_ERR(phy) : 0;
		}
		}

		/* New binding */
		fixed_link_node = of_get_child_by_name(np, "fixed-link");

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