On Fri, May 01, 2020 at 03:29:54PM -0700, David Miller wrote:
> From: Andrew Lunn <and...@lunn.ch>
> Date: Wed, 29 Apr 2020 22:53:23 +0200
>
> > The change to polled IO for MDIO completion assumes that MII events
> > are only generated for MDIO transactions. However on some SoCs writing
> > to the MII_SPEED register can also trigger an MII event. As a result,
> > the next MDIO read has a pending MII event, and immediately reads the
> > data registers before it contains useful data. When the read does
> > complete, another MII event is posted, which results in the next read
> > also going wrong, and the cycle continues.
> >
> > By writing 0 to the MII_DATA register before writing to the speed
> > register, this MII event for the MII_SPEED is suppressed, and polled
> > IO works as expected.
> >
> > v2 - Only infec_enet_mii_init()
> >
> > Fixes: 29ae6bd1b0d8 ("net: ethernet: fec: Replace interrupt driven MDIO
> > with polled IO")
> > Reported-by: Andy Duan <fugang.d...@nxp.com>
> > Suggested-by: Andy Duan <fugang.d...@nxp.com>
> > Signed-off-by: Andrew Lunn <and...@lunn.ch>
>
> Hmmm, I reverted the Fixes: tag patch so you'll need to respin this I think.
Ah.
We wanted the fix reverting, but not that the fix was fixing. Sorry,
we were unclear.
Andrew
