[PATCH][NET] several cleanups and bugfixes for fec.c: preserve MII/RMII setting in fec_stop()

[Shawn Guo]

On Wed, Dec 07, 2011 at 11:42:28AM +0100, Lothar Waßmann wrote:
> Hi,
> 
> Shawn Guo writes:
> > On Tue, Dec 06, 2011 at 11:27:14AM +0100, Lothar Waßmann wrote:
> > > Additionally to setting the ETHER_EN bit in FEC_ECNTRL the MII/RMII
> > > setting in FEC_R_CNTRL needs to be preserved to keep the MII interface
> > 
> > s/MII/RMII?  From what I see from imx28 and imx6q RM, the reset state
> > for this setting is MII mode.
> > 
> > > functional.
> > > 
> > > Signed-off-by: Lothar Waßmann <LW at KARO-electronics.de>
> > > ---
> > >  drivers/net/ethernet/freescale/fec.c |    5 ++++-
> > >  1 files changed, 4 insertions(+), 1 deletions(-)
> > 
> > I assume this is fixing a problem you are seeing on imx28 only.
> > Do you see the problem on imx53/51?
> > 
> No. i.MX53 uses the RMII gasket which is not affected by resetting the
> controller. And imMX51 does not support RMII at all.
> 
> > > 
> > > diff --git a/drivers/net/ethernet/freescale/fec.c b/drivers/net/ethernet/freescale/fec.c
> > > index 11534b9..ab0afb5 100644
> > > --- a/drivers/net/ethernet/freescale/fec.c
> > > +++ b/drivers/net/ethernet/freescale/fec.c
> > > @@ -515,6 +515,7 @@ fec_stop(struct net_device *ndev)
> > >  	struct fec_enet_private *fep = netdev_priv(ndev);
> > >  	const struct platform_device_id *id_entry =
> > >  				platform_get_device_id(fep->pdev);
> > > +	u32 rmii_mode = readl(fep->hwp + FEC_R_CNTRL) & (1 << 8);
> > 
> > This bit is only available on ENET (imx28 and imx6q).  Do we want to
> > do the same thing for FEC (imx25/27/35/51/53)?
> > 
> No. AFAICT that's not necessary there.
> 
So you need to check it's actually running on ENET before accessing
the bit.

-- 
Regards,
Shawn