Re: [PATCH] net: dsa: qca8k: fix kernel panic with legacy mdio mapping

From: Ansuel Smith
Date: Sat Sep 11 2021 - 11:36:51 EST


On Sat, Sep 11, 2021 at 08:31:51AM -0700, Florian Fainelli wrote:
>
>
> On 9/11/2021 08:07, Ansuel Smith wrote:
> > When the mdio legacy mapping is used the mii_bus priv registred by DSA
>
> typo: registered
>
> > refer to the dsa switch struct instead of the qca8k_priv struct and
> > cause a kernel panic.
>
> typo: causes
>
> > Create dedicated function when the internal
> > dedicated mdio driver is used to proprely handle the 2 different
> > implementation.
>
> typo: properly
>
> >
> > Fixes: 759bafb8a322 ("net: dsa: qca8k: add support for internal phy and internal mdio")
> > Signed-off-by: Ansuel Smith <ansuelsmth@xxxxxxxxx>
> > ---
> > drivers/net/dsa/qca8k.c | 30 ++++++++++++++++++++++--------
> > 1 file changed, 22 insertions(+), 8 deletions(-)
> >
> > diff --git a/drivers/net/dsa/qca8k.c b/drivers/net/dsa/qca8k.c
> > index 1f63f50f73f1..a701323daf72 100644
> > --- a/drivers/net/dsa/qca8k.c
> > +++ b/drivers/net/dsa/qca8k.c
> > @@ -643,10 +643,8 @@ qca8k_mdio_busy_wait(struct mii_bus *bus, u32 reg, u32 mask)
> > }
> > static int
> > -qca8k_mdio_write(struct mii_bus *salve_bus, int phy, int regnum, u16 data)
> > +qca8k_mdio_write(struct mii_bus *bus, int phy, int regnum, u16 data)
> > {
> > - struct qca8k_priv *priv = salve_bus->priv;
> > - struct mii_bus *bus = priv->bus;
> > u16 r1, r2, page;
> > u32 val;
> > int ret;
> > @@ -682,10 +680,8 @@ qca8k_mdio_write(struct mii_bus *salve_bus, int phy, int regnum, u16 data)
> > }
> > static int
> > -qca8k_mdio_read(struct mii_bus *salve_bus, int phy, int regnum)
> > +qca8k_mdio_read(struct mii_bus *bus, int phy, int regnum)
> > {
> > - struct qca8k_priv *priv = salve_bus->priv;
> > - struct mii_bus *bus = priv->bus;
> > u16 r1, r2, page;
> > u32 val;
> > int ret;
> > @@ -726,6 +722,24 @@ qca8k_mdio_read(struct mii_bus *salve_bus, int phy, int regnum)
> > return ret;
> > }
> > +static int
> > +qca8k_internal_mdio_write(struct mii_bus *salve_bus, int phy, int regnum, u16 data)
> > +{
> > + struct qca8k_priv *priv = salve_bus->priv;
>
> You are only moving code here but while at it, mind fixing that typo?
>

I think I didn't understand what you mean here.
Sure I will fix the typo and sorry about it.
Aside from that anything wrong with the 2 new function or there is a
better fix that I can't think of.

> > + struct mii_bus *bus = priv->bus;
> > +
> > + return qca8k_mdio_write(bus, phy, regnum, data);
> > +}
> > +
> > +static int
> > +qca8k_internal_mdio_read(struct mii_bus *salve_bus, int phy, int regnum)
> > +{
> > + struct qca8k_priv *priv = salve_bus->priv;
> > + struct mii_bus *bus = priv->bus;
> > +
> > + return qca8k_mdio_read(bus, phy, regnum);
> > +}
> > +
> > static int
> > qca8k_phy_write(struct dsa_switch *ds, int port, int regnum, u16 data)
> > {
> > @@ -775,8 +789,8 @@ qca8k_mdio_register(struct qca8k_priv *priv, struct device_node *mdio)
> > bus->priv = (void *)priv;
> > bus->name = "qca8k slave mii";
> > - bus->read = qca8k_mdio_read;
> > - bus->write = qca8k_mdio_write;
> > + bus->read = qca8k_internal_mdio_read;
> > + bus->write = qca8k_internal_mdio_write;
> > snprintf(bus->id, MII_BUS_ID_SIZE, "qca8k-%d",
> > ds->index);
> >
>
> --
> Florian