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

Vladimir Oltean
2023-02-08T21:38:08Z

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;