Re: [PATCH net-next v4 0/4] Fix OdroidC2 Gigabit Tx link issue

[Yegor Yefremov]

Hi Russel,

On Fri, Jan 6, 2017 at 12:25 AM, Russell King - ARM Linux
<linux@xxxxxxxxxxxxxxx> wrote:
> On Mon, Nov 28, 2016 at 09:54:28AM -0800, Florian Fainelli wrote:
>> If we start supporting generic "enable", "disable" type of properties
>> with values that map directly to register definitions of the HW, we
>> leave too much room for these properties to be utilized to implement a
>> specific policy, and this is not acceptable.
>
> Another concern with this patch is that the existing phylib "set_eee"
> code is horribly buggy - it just translates the modes from userspace
> into the register value and writes them directly to the register with
> no validation.  So it's possible to set modes in the register that the
> hardware doesn't support, and have them advertised to the link partner.
>
> I have a patch which fixes that, restricting (as we do elsewhere) the
> advert according to the EEE supported capabilities retrieved from the
> PCS - maybe the problem here is that the PCS doesn't support support
> EEE in 1000baseT mode?
>
> Out of interest, which PHY is used on this platform?
>
> On the SolidRun boards, they're using AR8035, and have suffered this
> occasional link drop problem.  What has been found is that it seems to
> be to do with the timing parameters, and it seemed to only be 1000bT
> that was affected.  I don't remember off hand exactly which or what
> the change was they made to stabilise it though, but I can probabily
> find out tomorrow.

I have different boards with am335x and AR8035 and we had occasional
link drop with both 100 and 1000 speeds.

Yegor