Re: [PATCH 0/3] at803x: Add quirk to disable SmartEEE

[Russell King - ARM Linux admin <linux@armlinux.org.uk>]

On Fri, Jan 25, 2019 at 08:07:56PM +0100, Heiner Kallweit wrote:
> On 25.01.2019 19:48, Carlo Caione wrote:
> > On 25/01/19 13:06, Russell King - ARM Linux admin wrote:
> >> On Fri, Jan 25, 2019 at 12:55:10PM +0000, Carlo Caione wrote:
> >>> SmartEEE, compatible with IEEE802.3az standard, is designed to include
> >>> legacy MAC without EEE capability into the power saving system. SmartEEE
> >>> is enabled by default configuration on AR8031 after power-on or hardware
> >>> reset.
> >>>
> >>> Unfortunately this is proved causing issues for certain hw
> >>> configurations.  We add a quirk to optionally disable SmartEEE.
> >>
> >> It may be a good idea to detail what "certain hw configurations" are
> >> and/or what the "issues" are, so it's easier to find this if/when
> >> others encounter the same issue.
> > 
> > This fix was upstreamed from the imx downstream kernel so I do not have much informations on that but something is reported in the U-Boot fix for the same problem at [0] so I'll add more info in the next revision.
> > 
> > Cheers,
> > 
> > [0] https://patchwork.ozlabs.org/patch/1015783/
> > 
> Thanks for the link. According to the description SmartEEE works only if
> both link partners support it (hence are Atheros PHY's). I would assume
> that this usually isn't the case, shouldn't the feature be an opt-in
> therefore?

I'm not convinced about that - I've been using AtherOS SmartEEE with
i.MX6 for quite some time (I have patches which allow me to read out
the stats via ethtool, and configure it - they're specific to the
FEC driver though.)  SmartEEE works just like EEE for me, and I
notice no problems.

I have i.MX6 boards connected to Netgear GS116 and similar switches,
and also Marvell DSA switches on other platforms.

This is why I said above about "more detail".  Then maybe folk would
know what to look for to see whether there is a problem.

-- 
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
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