Re: [PATCH net-next v3 1/3] net: dsa: rzn1-a5psw: use a5psw_reg_rmw() to modify flooding resolution

Clément Léger
2023-02-09T08:38:08Z

Le Wed, 8 Feb 2023 23:37:57 +0200,
Vladimir Oltean <olteanv@gmail.com> a écrit :

> On Wed, Feb 08, 2023 at 05:17:47PM +0100, Clément Léger wrote:
> > .port_bridge_flags will be added and allows to modify the flood mask
> > independently for each port. Keeping the existing bridged_ports write
> > in a5psw_flooding_set_resolution() would potentially messed up this.
> > Use a read-modify-write to set that value and move bridged_ports
> > handling in bridge_port_join/leave.
> >
> > Signed-off-by: Clément Léger <clement.leger@bootlin.com>
> > ---
> > drivers/net/dsa/rzn1_a5psw.c | 12 ++++++------
> > 1 file changed, 6 insertions(+), 6 deletions(-)
> >
> > diff --git a/drivers/net/dsa/rzn1_a5psw.c b/drivers/net/dsa/rzn1_a5psw.c
> > index 919027cf2012..8b7d4a371f8b 100644
> > --- a/drivers/net/dsa/rzn1_a5psw.c
> > +++ b/drivers/net/dsa/rzn1_a5psw.c
> > @@ -299,13 +299,9 @@ static void a5psw_flooding_set_resolution(struct a5psw *a5psw, int port,
> > A5PSW_MCAST_DEF_MASK};
> > int i;
> >
> > - if (set)
> > - a5psw->bridged_ports |= BIT(port);
> > - else
> > - a5psw->bridged_ports &= ~BIT(port);
> > -
> > for (i = 0; i < ARRAY_SIZE(offsets); i++)
> > - a5psw_reg_writel(a5psw, offsets[i], a5psw->bridged_ports);
> > + a5psw_reg_rmw(a5psw, offsets[i], BIT(port),
> > + set ? BIT(port) : 0);
> > }
> >
> > static int a5psw_port_bridge_join(struct dsa_switch *ds, int port,
> > @@ -326,6 +322,8 @@ static int a5psw_port_bridge_join(struct dsa_switch *ds, int port,
> > a5psw_flooding_set_resolution(a5psw, port, true);
> > a5psw_port_mgmtfwd_set(a5psw, port, false);
> >
> > + a5psw->bridged_ports |= BIT(port);
> > +
> > return 0;
> > }
> >
> > @@ -334,6 +332,8 @@ static void a5psw_port_bridge_leave(struct dsa_switch *ds, int port,
> > {
> > struct a5psw *a5psw = ds->priv;
> >
> > + a5psw->bridged_ports &= ~BIT(port);
> > +
> > a5psw_flooding_set_resolution(a5psw, port, false);
> > a5psw_port_mgmtfwd_set(a5psw, port, true);
> >
> > --
> > 2.39.0
> >
>
> What about the a5psw_flooding_set_resolution() call for the CPU port, from a5psw_setup()?
> Isn't this an undocumented change? Does this logic in a5psw_port_bridge_leave() still work,
> now that bridged_ports will no longer contain BIT(A5PSW_CPU_PORT)?
>
> /* No more ports bridged */
> if (a5psw->bridged_ports == BIT(A5PSW_CPU_PORT))
> a5psw->br_dev = NULL;

You are right, this actually disallow to create a bridge multiple
times. I'll fix that.

--
Clément Léger,
Embedded Linux and Kernel engineer at Bootlin