Hi all, I'm investigating a network failure after kexec on the Renesas Koelsch and Salvator-XS development boards, using the sh-eth or ravb driver. During normal boot, the Ethernet interface is working fine: libphy: get_phy_c22_id:814: sh_mii: mdiobus_read() MII_PHYSID1 returned 34 libphy: get_phy_c22_id:824: sh_mii: mdiobus_read() MII_PHYSID2 returned 5431 libphy: get_phy_c22_id:832: sh_mii: phy_id = 0x00221537 libphy: get_phy_device:895: sh_mii: get_phy_c22_id() returned 0 fwnode_mdiobus_register_phy:109: sh_mii: get_phy_device() returned (ptrval) fwnode_mdiobus_phy_device_register:46: sh_mii: fwnode_irq_get() returned 191 libphy: mdiobus_register_gpiod:48: mdiodev->reset_gpio = (ptrval) mdio_bus ee700000.ethernet-ffffffff:01: mdiobus_register_device:88: assert MDIO reset libphy: mdio_device_reset:124: calling gpiod_set_value_cansleep(..., 1) mdio_bus ee700000.ethernet-ffffffff:01: phy_device_register:931: deassert PHY reset libphy: mdio_device_reset:124: calling gpiod_set_value_cansleep(..., 0) Micrel KSZ8041RNLI ee700000.ethernet-ffffffff:01: phy_probe:3026: deassert PHY reset libphy: mdio_device_reset:124: calling gpiod_set_value_cansleep(..., 0) fwnode_mdiobus_phy_device_register:75: sh_mii: phy_device_register() returned 0 fwnode_mdiobus_register_phy:137: sh_mii: fwnode_mdiobus_phy_device_register() returned 0 of_mdiobus_register:188: of_mdiobus_register_phy(sh_mii, /soc/ethernet@ee700000/ethernet-phy@1, 1) returned 0 sh-eth ee700000.ethernet eth0: Base address at 0xee700000, 2e:09:0a:00:6d:85, IRQ 126. When using kexec, the PHY reset is asserted before starting the new kernel: Micrel KSZ8041RNLI ee700000.ethernet-ffffffff:01: phy_detach:1759: assert PHY reset libphy: mdio_device_reset:124: calling gpiod_set_value_cansleep(..., 1) kexec_core: Starting new kernel Bye! The new kernel fails to probe the PHY, as the PHY reset is still asserted: libphy: get_phy_c22_id:814: sh_mii: mdiobus_read() MII_PHYSID1 returned 65535 libphy: get_phy_c22_id:824: sh_mii: mdiobus_read() MII_PHYSID2 returned 65535 libphy: get_phy_c22_id:832: sh_mii: phy_id = 0xffffffff libphy: get_phy_device:895: sh_mii: get_phy_c22_id() returned -19 fwnode_mdiobus_register_phy:109: sh_mii: get_phy_device() returned -ENODEV of_mdiobus_register:188: of_mdiobus_register_phy(sh_mii, /soc/ethernet@ee700000/ethernet-phy@1, 1) returned -19 mdio_bus ee700000.ethernet-ffffffff: MDIO device at address 1 is missing. sh-eth ee700000.ethernet eth0: Base address at 0xee700000, 2e:09:0a:00:6d:85, IRQ 126. This issue can also be reproduced using unbind: # echo ee700000.ethernet > /sys/bus/platform/drivers/sh-eth/unbind sh-eth ee700000.ethernet eth0: Link is Down Micrel KSZ8041RNLI ee700000.ethernet-ffffffff:01: phy_detach:1759: assert PHY reset libphy: mdio_device_reset:124: calling gpiod_set_value_cansleep(..., 1) Micrel KSZ8041RNLI ee700000.ethernet-ffffffff:01: phy_remove:3120: assert PHY reset libphy: mdio_device_reset:124: calling gpiod_set_value_cansleep(..., 1) mdio_bus ee700000.ethernet-ffffffff:01: phy_device_remove:974: assert PHY reset libphy: mdio_device_reset:124: calling gpiod_set_value_cansleep(..., 1) and bind: # echo ee700000.ethernet > /sys/bus/platform/drivers/sh-eth/bind (same log as kexec boot) I think fwnode_mdiobus_register_phy() should do the PHY reset (assert + deassert) before calling get_phy_device(), but currently that happens in phy_device_register(), which is called later. Thanks for your comments! Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds