net: dsa: make phylink-related OF properties mandatory on DSA and CPU ports
Early DSA drivers were kind of simplistic in that they assumed a fairly narrow hardware layout. User ports would have integrated PHYs at an internal MDIO address that is derivable from the port number, and shared (DSA and CPU) ports would have an MII-style (serial or parallel) connection to another MAC. Phylib and then phylink were used to drive the internal PHYs, and this needed little to no description through the platform data structures. Bringing up the shared ports at the maximum supported link speed was the responsibility of the drivers. As a result of this, when these early drivers were converted from platform data to the new DSA OF bindings, there was no link information translated into the first DT bindings. https://lore.kernel.org/all/YtXFtTsf++AeDm1l@lunn.ch/ Later, phylink was adopted for shared ports as well, and today we have a workaround in place, introduced by commit a20f9970 ("net: dsa: Don't instantiate phylink for CPU/DSA ports unless needed"). There, DSA checks for the presence of phy-handle/fixed-link/managed OF properties, and if missing, phylink registration would be skipped. This is because phylink is optional for some drivers (the shared ports already work without it), but the process of starting to register a port with phylink is irreversible: if phylink_create() fails to find the fwnode properties it needs, it bails out and it leaves the ports inoperational (because phylink expects ports to be initially down, so DSA necessarily takes them down, and doesn't know how to put them back up again). DSA being a common framework, new drivers opt into this workaround willy-nilly, but the ideal behavior from the DSA core's side would have been to not interfere with phylink's process of failing at all. This isn't possible because of regression concerns with pre-phylink DT blobs, but at least DSA should put a stop to the proliferation of more of such cases that rely on the workaround to skip phylink registration, and sanitize the environment that new drivers work in. To that end, create a list of compatible strings for which the workaround is preserved, and don't apply the workaround for any drivers outside that list (this includes new drivers). In some cases, we make the assumption that even existing drivers don't rely on DSA's workaround, and we do this by looking at the device trees in which they appear. We can't fully know what is the situation with downstream DT blobs, but we can guess the overall trend by studying the DT blobs that were submitted upstream. If there are upstream blobs that have lacking descriptions, we take it as very likely that there are many more downstream blobs that do so too. If all upstream blobs have complete descriptions, we take that as a hint that the driver is a candidate for enforcing strict DT bindings (considering that most bindings are copy-pasted). If there are no upstream DT blobs, we take the conservative route of allowing the workaround, unless the driver maintainer instructs us otherwise. The driver situation is as follows: ar9331 ~~~~~~ compatible strings: - qca,ar9331-switch 1 occurrence in mainline device trees, part of SoC dtsi (arch/mips/boot/dts/qca/ar9331.dtsi), description is not problematic. Verdict: opt into strict DT bindings and out of workarounds. b53 ~~~ compatible strings: - brcm,bcm5325 - brcm,bcm53115 - brcm,bcm53125 - brcm,bcm53128 - brcm,bcm5365 - brcm,bcm5389 - brcm,bcm5395 - brcm,bcm5397 - brcm,bcm5398 - brcm,bcm53010-srab - brcm,bcm53011-srab - brcm,bcm53012-srab - brcm,bcm53018-srab - brcm,bcm53019-srab - brcm,bcm5301x-srab - brcm,bcm11360-srab - brcm,bcm58522-srab - brcm,bcm58525-srab - brcm,bcm58535-srab - brcm,bcm58622-srab - brcm,bcm58623-srab - brcm,bcm58625-srab - brcm,bcm88312-srab - brcm,cygnus-srab - brcm,nsp-srab - brcm,omega-srab - brcm,bcm3384-switch - brcm,bcm6328-switch - brcm,bcm6368-switch - brcm,bcm63xx-switch I've found at least these mainline DT blobs with problems: arch/arm/boot/dts/bcm47094-linksys-panamera.dts - lacks phy-mode arch/arm/boot/dts/bcm47189-tenda-ac9.dts - lacks phy-mode and fixed-link arch/arm/boot/dts/bcm47081-luxul-xap-1410.dts arch/arm/boot/dts/bcm47081-luxul-xwr-1200.dts arch/arm/boot/dts/bcm47081-buffalo-wzr-600dhp2.dts - lacks phy-mode and fixed-link arch/arm/boot/dts/bcm47094-luxul-xbr-4500.dts arch/arm/boot/dts/bcm4708-smartrg-sr400ac.dts arch/arm/boot/dts/bcm4708-luxul-xap-1510.dts arch/arm/boot/dts/bcm953012er.dts arch/arm/boot/dts/bcm4708-netgear-r6250.dts arch/arm/boot/dts/bcm4708-buffalo-wzr-1166dhp-common.dtsi arch/arm/boot/dts/bcm4708-luxul-xwc-1000.dts arch/arm/boot/dts/bcm47094-luxul-abr-4500.dts - lacks phy-mode and fixed-link arch/arm/boot/dts/bcm53016-meraki-mr32.dts - lacks phy-mode Verdict: opt into DSA workarounds. bcm_sf2 ~~~~~~~ compatible strings: - brcm,bcm4908-switch - brcm,bcm7445-switch-v4.0 - brcm,bcm7278-switch-v4.0 - brcm,bcm7278-switch-v4.8 A single occurrence in mainline (arch/arm64/boot/dts/broadcom/bcm4908/bcm4908.dtsi), part of a SoC dtsi, valid description. Florian Fainelli explains that most of the bcm_sf2 device trees lack a full description for the internal IMP ports. Verdict: opt the BCM4908 into strict DT bindings, and opt the rest into the workarounds. Note that even though BCM4908 has strict DT bindings, it still does not register with phylink on the IMP port due to it implementing ->adjust_link(). hellcreek ~~~~~~~~~ compatible strings: - hirschmann,hellcreek-de1soc-r1 No occurrence in mainline device trees. Kurt Kanzenbach explains that the downstream device trees lacked phy-mode and fixed link, and needed work, but were fixed in the meantime. Verdict: opt into strict DT bindings and out of workarounds. lan9303 ~~~~~~~ compatible strings: - smsc,lan9303-mdio - smsc,lan9303-i2c 1 occurrence in mainline device trees: arch/arm/boot/dts/imx53-kp-hsc.dts - no phy-mode, no fixed-link Verdict: opt out of strict DT bindings and into workarounds. lantiq_gswip ~~~~~~~~~~~~ compatible strings: - lantiq,xrx200-gswip - lantiq,xrx300-gswip - lantiq,xrx330-gswip No occurrences in mainline device trees. Martin Blumenstingl confirms that the downstream OpenWrt device trees lack a proper fixed-link and need work, and that the incomplete description can even be seen in the example from Documentation/devicetree/bindings/net/dsa/lantiq-gswip.txt. Verdict: opt out of strict DT bindings and into workarounds. microchip ksz ~~~~~~~~~~~~~ compatible strings: - microchip,ksz8765 - microchip,ksz8794 - microchip,ksz8795 - microchip,ksz8863 - microchip,ksz8873 - microchip,ksz9477 - microchip,ksz9897 - microchip,ksz9893 - microchip,ksz9563 - microchip,ksz8563 - microchip,ksz9567 - microchip,lan9370 - microchip,lan9371 - microchip,lan9372 - microchip,lan9373 - microchip,lan9374 5 occurrences in mainline device trees, all descriptions are valid. But we had a snafu for the ksz8795 and ksz9477 drivers where the phy-mode property would be expected to be located directly under the 'switch' node rather than under a port OF node. It was fixed by commit edecfa98 ("net: dsa: microchip: look for phy-mode in port nodes"). The driver still has compatibility with the old DT blobs. The lan937x support was added later than the above snafu was fixed, and even though it has support for the broken DT blobs by virtue of sharing a common probing function, I'll take it that its DT blobs are correct. Verdict: opt lan937x into strict DT bindings, and the others out. mt7530 ~~~~~~ compatible strings - mediatek,mt7621 - mediatek,mt7530 - mediatek,mt7531 Multiple occurrences in mainline device trees, one is part of an SoC dtsi (arch/mips/boot/dts/ralink/mt7621.dtsi), all descriptions are fine. Verdict: opt into strict DT bindings and out of workarounds. mv88e6060 ~~~~~~~~~ compatible string: - marvell,mv88e6060 no occurrences in mainline, nobody knows anybody who uses it. Verdict: opt out of strict DT bindings and into workarounds. mv88e6xxx ~~~~~~~~~ compatible strings: - marvell,mv88e6085 - marvell,mv88e6190 - marvell,mv88e6250 Device trees that have incomplete descriptions of CPU or DSA ports: arch/arm64/boot/dts/freescale/imx8mq-zii-ultra.dtsi - lacks phy-mode arch/arm64/boot/dts/marvell/cn9130-crb.dtsi - lacks phy-mode and fixed-link arch/arm/boot/dts/vf610-zii-ssmb-spu3.dts - lacks phy-mode arch/arm/boot/dts/kirkwood-mv88f6281gtw-ge.dts - lacks phy-mode arch/arm/boot/dts/vf610-zii-spb4.dts - lacks phy-mode arch/arm/boot/dts/vf610-zii-cfu1.dts - lacks phy-mode arch/arm/boot/dts/vf610-zii-dev-rev-c.dts - lacks phy-mode on CPU port, fixed-link on DSA ports arch/arm/boot/dts/vf610-zii-dev-rev-b.dts - lacks phy-mode on CPU port arch/arm/boot/dts/armada-381-netgear-gs110emx.dts - lacks phy-mode arch/arm/boot/dts/vf610-zii-scu4-aib.dts - lacks fixed-link on xgmii DSA ports and/or in-band-status on 2500base-x DSA ports, and phy-mode on CPU port arch/arm/boot/dts/imx6qdl-gw5904.dtsi - lacks phy-mode and fixed-link arch/arm/boot/dts/armada-385-clearfog-gtr-l8.dts - lacks phy-mode and fixed-link arch/arm/boot/dts/vf610-zii-ssmb-dtu.dts - lacks phy-mode arch/arm/boot/dts/kirkwood-dir665.dts - lacks phy-mode arch/arm/boot/dts/kirkwood-rd88f6281.dtsi - lacks phy-mode arch/arm/boot/dts/orion5x-netgear-wnr854t.dts - lacks phy-mode and fixed-link arch/arm/boot/dts/armada-388-clearfog.dts - lacks phy-mode arch/arm/boot/dts/armada-xp-linksys-mamba.dts - lacks phy-mode arch/arm/boot/dts/armada-385-linksys.dtsi - lacks phy-mode arch/arm/boot/dts/imx6q-b450v3.dts arch/arm/boot/dts/imx6q-b850v3.dts - has a phy-handle but not a phy-mode? arch/arm/boot/dts/armada-370-rd.dts - lacks phy-mode arch/arm/boot/dts/kirkwood-linksys-viper.dts - lacks phy-mode arch/arm/boot/dts/imx51-zii-rdu1.dts - lacks phy-mode arch/arm/boot/dts/imx51-zii-scu2-mezz.dts - lacks phy-mode arch/arm/boot/dts/imx6qdl-zii-rdu2.dtsi - lacks phy-mode arch/arm/boot/dts/armada-385-clearfog-gtr-s4.dts - lacks phy-mode and fixed-link Verdict: opt out of strict DT bindings and into workarounds. ocelot ~~~~~~ compatible strings: - mscc,vsc9953-switch - felix (arch/arm64/boot/dts/freescale/fsl-ls1028a.dtsi) is a PCI device, has no compatible string 2 occurrences in mainline, both are part of SoC dtsi and complete. Verdict: opt into strict DT bindings and out of workarounds. qca8k ~~~~~ compatible strings: - qca,qca8327 - qca,qca8328 - qca,qca8334 - qca,qca8337 5 occurrences in mainline device trees, none of the descriptions are problematic. Verdict: opt into strict DT bindings and out of workarounds. realtek ~~~~~~~ compatible strings: - realtek,rtl8366rb - realtek,rtl8365mb 2 occurrences in mainline, both descriptions are fine, additionally rtl8365mb.c has a comment "The device tree firmware should also specify the link partner of the extension port - either via a fixed-link or other phy-handle." Verdict: opt into strict DT bindings and out of workarounds. rzn1_a5psw ~~~~~~~~~~ compatible strings: - renesas,rzn1-a5psw One single occurrence, part of SoC dtsi (arch/arm/boot/dts/r9a06g032.dtsi), description is fine. Verdict: opt into strict DT bindings and out of workarounds. sja1105 ~~~~~~~ Driver already validates its port OF nodes in sja1105_parse_ports_node(). Verdict: opt into strict DT bindings and out of workarounds. vsc73xx ~~~~~~~ compatible strings: - vitesse,vsc7385 - vitesse,vsc7388 - vitesse,vsc7395 - vitesse,vsc7398 2 occurrences in mainline device trees, both descriptions are fine. Verdict: opt into strict DT bindings and out of workarounds. xrs700x ~~~~~~~ compatible strings: - arrow,xrs7003e - arrow,xrs7003f - arrow,xrs7004e - arrow,xrs7004f no occurrences in mainline, we don't know. Verdict: opt out of strict DT bindings and into workarounds. Because there is a pattern where newly added switches reuse existing drivers more often than introducing new ones, I've opted for deciding who gets to opt into the workaround based on an OF compatible match table in the DSA core. The alternative would have been to add another boolean property to struct dsa_switch, like configure_vlan_while_not_filtering. But this avoids situations where sometimes driver maintainers obfuscate what goes on by sharing a common probing function, and therefore making new switches inherit old quirks. Side note, we also warn about missing properties for drivers that rely on the workaround. This isn't an indication that we'll break compatibility with those DT blobs any time soon, but is rather done to raise awareness about the change, for future DT blob authors. Cc: Rob Herring <robh+dt@kernel.org> Cc: Frank Rowand <frowand.list@gmail.com> Acked-by: Alvin Šipraga <alsi@bang-olufsen.dk> # realtek Signed-off-by:Vladimir Oltean <vladimir.oltean@nxp.com> Signed-off-by:
Jakub Kicinski <kuba@kernel.org>
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