Re: [RFC PATCH net-next 4/4] net: phy: added master-slave config and cable diagnostics for Lan937x

[<Arun.Ramadoss@microchip.com>]

On Mon, 2022-02-28 at 14:12 +0000, Russell King (Oracle) wrote:
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> On Mon, Feb 28, 2022 at 07:35:10PM +0530, Arun Ramadoss wrote:
> > To configure the Lan937x T1 phy as master or slave using the
> > ethtool -s
> > <dev> master-slave <forced-master/forced-slave>, the config_aneg
> > and
> > read status functions are added. And for the cable-diagnostics,
> > used the
> > lan87xx routines.
> > 
> > Signed-off-by: Prasanna Vengateshan <
> > prasanna.vengateshan@microchip.com>
> > Signed-off-by: Arun Ramadoss <arun.ramadoss@microchip.com>
> > ---
> >  drivers/net/phy/microchip_t1.c | 75
> > ++++++++++++++++++++++++++++++++++
> >  1 file changed, 75 insertions(+)
> > 
> > diff --git a/drivers/net/phy/microchip_t1.c
> > b/drivers/net/phy/microchip_t1.c
> > index 634a1423182a..3a0d4c4fab0a 100644
> > --- a/drivers/net/phy/microchip_t1.c
> > +++ b/drivers/net/phy/microchip_t1.c
> > @@ -81,6 +81,9 @@
> >  #define T1_REG_BANK_SEL                      8
> >  #define T1_REG_ADDR_MASK             0xFF
> > 
> > +#define T1_MODE_STAT_REG             0x11
> > +#define T1_LINK_UP_MSK                       BIT(0)
> > +
> >  #define DRIVER_AUTHOR        "Nisar Sayed <
> > nisar.sayed@microchip.com>"
> >  #define DRIVER_DESC  "Microchip LAN87XX/LAN937x T1 PHY driver"
> > 
> > @@ -435,6 +438,11 @@ static int lan_phy_config_init(struct
> > phy_device *phydev)
> >       if (rc < 0)
> >               phydev_err(phydev, "failed to initialize phy\n");
> > 
> > +     phydev->duplex = DUPLEX_FULL;
> > +     phydev->speed = SPEED_100;
> > +     phydev->pause = 0;
> > +     phydev->asym_pause = 0;
> 
> Shouldn't this be done in lan937x_read_status()?
> 
> Have you tested this patch with various invocations of ethtool -s ?
> E.g. autoneg on, autoneg off at various forced speeds, both suitable
> for the PHY and unsuitable? Are all these sensibly handled?
> 
Thanks for the comment.

LAN937x is 100BaseT1 Phy and it doesn't provide option for changing
speed and autonegotiation. Since it is fixed and not going to change
using ethtool -s command, I added it in the config_init routine. I took
the drivers/net/phy/nxp-tja11xx as reference in which speed is
initialised in config_init routine. I tested the patch using the
ethtool -s for changing the master/slave configuration. For other
change like speed/duplex setting, driver will not make change. When I
execute ethtool <dev>, it returns the default value 100Mbps, Full
duplex.
If lan937x_read_status( ) is the suitable place, then I will move it
there. 

> Thanks.
> 
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