Re: [PATCH net-next] net: dsa: mt7530: do not set MT7530_P5_DIS when PHY muxing is being used

[Arınç ÜNAL]

On 27.04.2024 16:31, Andrew Lunn wrote:
> On Sat, Apr 27, 2024 at 02:24:42PM +0300, Arınç ÜNAL via B4 Relay wrote:
> > From: Arınç ÜNAL <arinc.unal@xxxxxxxxxx>
> >
> > When the PHY muxing feature is in use, port 5 won't be defined in the
> > device tree. Because of this, the type member of the dsa_port structure for
> > this port will be assigned DSA_PORT_TYPE_UNUSED. The dsa_port_setup()
> > function calls ds->ops->port_disable() when the port type is
> > DSA_PORT_TYPE_UNUSED.
> >
> > The MT7530_P5_DIS bit is unset when PHY muxing is being used.
> > mt7530_port_disable() which is assigned to ds->ops->port_disable() is
> > called afterwards. Currently, mt7530_port_disable() sets MT7530_P5_DIS
> > which breaks network connectivity when PHY muxing is being used.
> >
> > Therefore, do not set MT7530_P5_DIS when PHY muxing is being used.
> >
> > Fixes: 377174c5760c ("net: dsa: mt7530: move MT753X_MTRAP operations for MT7530")
> > Reported-by: Daniel Golle <daniel@xxxxxxxxxxxxxx>
> > Signed-off-by: Arınç ÜNAL <arinc.unal@xxxxxxxxxx>
> > ---
> > Hello.
> >
> > I've sent this to net-next as the patch it fixes is on the current
> > development cycle.
> > ---
> >   drivers/net/dsa/mt7530.c | 2 +-
> >   1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/net/dsa/mt7530.c b/drivers/net/dsa/mt7530.c
> > index 2b9f904a98f0..07b6da3ae97c 100644
> > --- a/drivers/net/dsa/mt7530.c
> > +++ b/drivers/net/dsa/mt7530.c
> > @@ -1220,7 +1220,7 @@ mt7530_port_disable(struct dsa_switch *ds, int port)
> >   	if (priv->id != ID_MT7530 && priv->id != ID_MT7621)
> >   		return;
> >   
> > -	if (port == 5)
> > +	if (port == 5 && priv->p5_mode == GMAC5)
> >   		mt7530_set(priv, MT753X_MTRAP, MT7530_P5_DIS);
>
>
> It might be worth a comment. It is not obvious that
> priv->p5_mode == GMAC5 means the PHY MUX is being used.
> mt7530_setup_port5() thinks it is sufficiently obscure that
> it comments each case.

priv->p5_mode == GMAC5 means PHY muxing is not being used. That is why
MT7530_P5_DIS is set when priv->p5_mode is GMAC5. Anyway, I believe this
proves your point.

Arınç