Subject: Re: [PATCH 0/4] Attempt to fix regression with AR8035 speed downgrade

From: Russell King - ARM Linux admin <[email-masked]>
Date: Sun, 22 Sep 2019 13:56:24 +0100

On Sun, Sep 22, 2019 at 11:59:32AM +0100, Russell King - ARM Linux admin wrote:
> Commentary: what is not yet known is whether the AR8035 restores the
>             advertisement register when the link goes down to the
> 	    previous state.

I've just found my 2-pair cable, and it appears that the AR8035 does
indeed restore the advertisement register.

Using the 2-pair cable (which takes a while for the link to come up
at 100mbit) results in register 9 becoming zero:

   1140 796d 004d d072 15e1 c1e1 000d 2001
   0000 0000 0800 0000 0000 4007 b29a a000
   0862 7c30 0000 dc20 082c 0000 04e8 0000
   3200 3000 0000 060d 0000 0005 2d47 8100.

Disconnecting the 2-pair, and connecting a 4-pair cable results in a
gigabit link with the advertisement restored:

   1140 796d 004d d072 15e1 c1e1 000d 2001
   0000 0200 2800 0000 0000 4007 b29a a000
   0862 bc50 0000 dc00 082c 0000 04e8 0000
   3200 3000 0000 060e 0000 0005 2d47 8100.

Note that register 0x11 bit 5 reports when downshift is active.

-- 
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
FTTC broadband for 0.8mile line in suburbia: sync at 12.1Mbps down 622kbps up
According to speedtest.net: 11.9Mbps down 500kbps up