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alistair23-linux/arch/riscv
Sagar Shrikant Kadam be969b7cfb
dts: phy: fix missing mdio device and probe failure of vsc8541-01 device
HiFive unleashed A00 board has VSC8541-01 ethernet phy, this device is
identified as a Revision B device as described in device identification
registers. In order to use this phy in the unmanaged mode, it requires
a specific reset sequence of logical 0-1-0-1 transition on the NRESET pin
as documented here [1].

Currently, the bootloader (fsbl or u-boot-spl) takes care of the phy reset.
If due to some reason the phy device hasn't received the reset by the prior
stages before the linux macb driver comes into the picture, the MACB mii
bus gets probed but the mdio scan fails and is not even able to read the
phy ID registers. It gives an error message:

"libphy: MACB_mii_bus: probed
mdio_bus 10090000.ethernet-ffffffff: MDIO device at address 0 is missing."

Thus adding the device OUI (Organizationally Unique Identifier) to the phy
device node helps to probe the phy device.

[1]: VSC8541-01 datasheet:
https://www.mouser.com/ds/2/523/Microsemi_VSC8541-01_Datasheet_10496_V40-1148034.pdf

Signed-off-by: Sagar Shrikant Kadam <sagar.kadam@sifive.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-01-13 20:58:50 -08:00
..
boot dts: phy: fix missing mdio device and probe failure of vsc8541-01 device 2021-01-13 20:58:50 -08:00
configs RISC-V: Add EFI stub support. 2020-10-02 14:31:21 -07:00
include riscv: Fixup CONFIG_GENERIC_TIME_VSYSCALL 2021-01-12 20:34:44 -08:00
kernel riscv: Fixup CONFIG_GENERIC_TIME_VSYSCALL 2021-01-12 20:34:44 -08:00
lib riscv: provide memmove implementation 2020-12-10 17:27:54 -08:00
mm riscv: Fix KASAN memory mapping. 2021-01-13 20:50:11 -08:00
net treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
Kbuild riscv: Allow device trees to be built into the kernel 2020-05-18 11:38:05 -07:00
Kconfig RISC-V Patches for the 5.11 Merge Window, Part 1 2020-12-18 10:43:07 -08:00
Kconfig.debug RISC-V: Remove EARLY_PRINTK support 2018-12-17 10:23:46 -08:00
Kconfig.socs clk: sifive: Use common name for prci configuration 2020-12-16 12:22:59 -08:00
Makefile riscv: Clean up boot dir 2020-11-09 11:54:45 -08:00