Re: Question: pause mode disabled for marvell 88e151x phy

From: Russell King - ARM Linux admin
Date: Wed Jan 23 2019 - 17:42:00 EST


On Sat, Jan 05, 2019 at 11:28:19AM +0800, Yunsheng Lin wrote:
> On 2018/12/17 22:36, Russell King - ARM Linux wrote:
> > I'll try to do further diagnosis over Christmas in case I've missed
> > something, but I suspect it may be one of those "weird behaviour" issues
> > where the safest action is to disable pause mode as per my commit -
> > which is far saner than having mismatched pause status on either end
> > of a link. However, given that Marvell specs are all NDA-only, it's
> > very difficult to investigate beyond "this is the observed behaviour".
>
> Hi,
>
> Is there any update on the further diagnosis?

Hi,

I've finally been able to do some further diagnosis (with a 'scope).
It would appear that the network adapter had PHY polling enabled,
which meant that it overwrote the PHYs advertisement register
during negotiation. I thought I'd checked that scenario, but alas
clearing the PHY poll enable bit on its own doesn't stop it polling!

I'll send a revert for the commit shortly.

--
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