Re: [BISECTED, REGRESSION] Broken networking on MIPS/OCTEON EdgeRouter Lite

[Aaro Koskinen <aaro.koskinen@iki.fi>]

Hi,

On Fri, Mar 22, 2019 at 12:15:06PM +0530, Vinod Koul wrote:
> On 22-03-19, 02:21, Aaro Koskinen wrote:
> > When booting v5.1-rc1 on EdgeRouter Lite (MIPS/OCTEON), with at803x phy
> > driver enabled, networking no longer works - I even need to go physically
> > power cycle the board before getting networking to work again (otherwise
> > bootloader cannot tftp an older working image).
> > 
> > Bisected to:
> > 
> > 	commit 6d4cd041f0af5b4c8fc742b4a68eac22e420e28c
> > 	Author: Vinod Koul <vkoul@kernel.org>
> > 	Date:   Thu Feb 21 15:53:15 2019 +0530
> > 
> > 	    net: phy: at803x: disable delay only for RGMII mode
> 
> Hello,
> 
> So with cd28d1d6e52e ("net: phy: at803x: Disable phy delay for RGMII
> mode") it works for you but not 6d4cd041f0af ("net: phy: at803x: disable
> delay only for RGMII mode"). That is bit more weird case :)

Yes, I guess it's the new "disable by default" behaviour that breaks it.

> So does the ethernet expect RGMII mode or RGMII_ID mode here, looks like
> disable delay is expected as well?

The OCTEON HW code knows only about RGMII. And looking at
octeon ethernet staging driver it does phy connect always with
PHY_INTERFACE_MODE_GMII. I did some experimentation, and it seems that
with PHY_INTERFACE_MODE_RGMII_RXID it starts to work.. In the DT we have
for ethernet for this board:

	rx-delay = <0>;
	tx-delay = <0x10>;

which I guess matches, or does this make any sense?

> Can you point me to the DT node as well..

arch/mips/boot/dts/cavium-octeon/ubnt_e100.dts

A.