[bug report] sunxi: H6: no ethernet on Orange Pi One Plus

[Anne Macedo]

On Tue, Jul 04, 2023 at 11:22:29PM +0000, Anne Macedo wrote:
> Hey!
> 
> I'm trying to bake Linux images for the Orange Pi One Plus using Yocto.
> Everything works fine, except for Ethernet.
> 
> On the u-boot prompt:
> 
> => dhcp
> No ethernet found.
> 
> After adding:
> 
> CONFIG_SPL_SPI_SUNXI=y
> CONFIG_SUN8I_EMAC=y
> 
> to configs/orangepi_one_plus_defconfig, I started seeing this error:
> 
> => dhcp
> sun8i_emac_eth_start: Timeout
> 
> I saw this other bug report but I couldn't really understand what has
> been made to fix this issue [1].
> 
> More context here [2].
> 
> [1] https://lists.denx.de/pipermail/u-boot/2021-June/451357.html
> [2] https://github.com/linux-sunxi/meta-sunxi/issues/387
> 
> Regards,
> Anne

Just wanted to share a summary of my findings about the ethernet on the
Orange Pi One Plus (Allwinner H6).

1. PMIC should not be disabled. I tested and if I disable PMIC, MAC
never turns on, even if I force the gpio PD6 pin to be on. When building
tfa, use SUNXI_SETUP_REGULATORS=1 or just don't pass it.

2. These configs are needed on configs/orangepi_one_plus_defconfig

CONFIG_SPL_SPI_SUNXI=y
CONFIG_SUN8I_EMAC=y

3. With this config, there's this strange behavior where ethernet is
only detected after a crash:

# Fresh boot
Net:   Could not get PHY for ethernet at 5020000: addr 1
No ethernet found.

# Forcing the board to crash
=> mii dump
"Synchronous Abort" handler, esr 0x96000044

Code: 32000021 d5033fbf 91408013 f9481a60 (b9004801) 
Resetting CPU ...

resetting ...

# Reboot
Net:   eth0: ethernet at 5020000

4. I'm testing CONFIG_MACPWR="PD6" and that successfully enabled MAC on
u-boot (I see the LEDs turning on). However, I see the behaviour from #3
but crash-rebooting doesn't seem to enable ethernet...

Regards,
Anne