Subject: Re: [PATCH net] ixgbe: fix probing of multi-port devices with one MDIO

From: Jesse Brandeburg <[email-masked]>
Date: Fri, 16 Oct 2020 17:48:07 -0700

Jakub Kicinski wrote:

> On Sat, 17 Oct 2020 01:50:59 +0200 Ian Kumlien wrote:
> > On Sat, Oct 17, 2020 at 1:20 AM Jakub Kicinski <[email-masked]> wrote:
> > > Ian reports that after upgrade from v5.8.14 to v5.9 only one
> > > of his 4 ixgbe netdevs appear in the system.
> > >
> > > Quoting the comment on ixgbe_x550em_a_has_mii():
> > >  * Returns true if hw points to lowest numbered PCI B:D.F x550_em_a device in
> > >  * the SoC.  There are up to 4 MACs sharing a single MDIO bus on the x550em_a,
> > >  * but we only want to register one MDIO bus.
> > >
> > > This matches the symptoms, since the return value from
> > > ixgbe_mii_bus_init() is no longer ignored we need to handle
> > > the higher ports of x550em without an error.  
> > 
> > Nice, that fixes it!
> > 
> > You can add a:
> > Tested-by: Ian Kumlien <[email-masked]>
> 
> Will do, thanks!
> 
> Tony, should I apply directly to net?

Thank you Kuba!

Seems like a pretty straight forward bug-fix. I recommend
you apply it directly.

Acked-by: Jesse Brandeburg <[email-masked]>