Re: [PATCH net-next 3/5 v2] net: dsa: rtl8366rb: Support disabling learning

[Vladimir Oltean <olteanv@gmail.com>]

On Mon, Aug 30, 2021 at 11:48:57PM +0200, Linus Walleij wrote:
> The RTL8366RB hardware supports disabling learning per-port
> so let's make use of this feature. Rename some unfortunately
> named registers in the process.
> 
> Suggested-by: Vladimir Oltean <olteanv@gmail.com>
> Cc: Alvin Šipraga <alsi@bang-olufsen.dk>
> Cc: Mauri Sandberg <sandberg@mailfence.com>
> Cc: DENG Qingfang <dqfext@gmail.com>
> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
> ---
> ChangeLog v1->v2:
> - New patch suggested by Vladimir.
> ---
>  drivers/net/dsa/rtl8366rb.c | 47 +++++++++++++++++++++++++++++++++----
>  1 file changed, 42 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/net/dsa/rtl8366rb.c b/drivers/net/dsa/rtl8366rb.c
> index 8b040440d2d4..2cadd3e57e8b 100644
> --- a/drivers/net/dsa/rtl8366rb.c
> +++ b/drivers/net/dsa/rtl8366rb.c
> @@ -14,6 +14,7 @@
>  
>  #include <linux/bitops.h>
>  #include <linux/etherdevice.h>
> +#include <linux/if_bridge.h>
>  #include <linux/interrupt.h>
>  #include <linux/irqdomain.h>
>  #include <linux/irqchip/chained_irq.h>
> @@ -42,9 +43,12 @@
>  /* Port Enable Control register */
>  #define RTL8366RB_PECR				0x0001
>  
> -/* Switch Security Control registers */
> -#define RTL8366RB_SSCR0				0x0002
> -#define RTL8366RB_SSCR1				0x0003
> +/* Switch per-port learning disablement register */
> +#define RTL8366RB_PORT_LEARNDIS_CTRL		0x0002
> +
> +/* Security control, actually aging register */
> +#define RTL8366RB_SECURITY_CTRL			0x0003
> +
>  #define RTL8366RB_SSCR2				0x0004
>  #define RTL8366RB_SSCR2_DROP_UNKNOWN_DA		BIT(0)
>  
> @@ -912,12 +916,12 @@ static int rtl8366rb_setup(struct dsa_switch *ds)
>  		rb->max_mtu[i] = 1532;
>  
>  	/* Enable learning for all ports */
> -	ret = regmap_write(smi->map, RTL8366RB_SSCR0, 0);
> +	ret = regmap_write(smi->map, RTL8366RB_PORT_LEARNDIS_CTRL, 0);

So the expected behavior for standalone ports would be to _disable_
learning. In rtl8366rb_setup, they are standalone.

>  	if (ret)
>  		return ret;
>  
>  	/* Enable auto ageing for all ports */
> -	ret = regmap_write(smi->map, RTL8366RB_SSCR1, 0);
> +	ret = regmap_write(smi->map, RTL8366RB_SECURITY_CTRL, 0);
>  	if (ret)
>  		return ret;
>  
> @@ -1148,6 +1152,37 @@ rtl8366rb_port_disable(struct dsa_switch *ds, int port)
>  	rb8366rb_set_port_led(smi, port, false);
>  }
>  
> +static int
> +rtl8366rb_port_pre_bridge_flags(struct dsa_switch *ds, int port,
> +				struct switchdev_brport_flags flags,
> +				struct netlink_ext_ack *extack)
> +{
> +	/* We support enabling/disabling learning */
> +	if (flags.mask & ~(BR_LEARNING))
> +		return -EINVAL;
> +
> +	return 0;
> +}
> +
> +static int
> +rtl8366rb_port_bridge_flags(struct dsa_switch *ds, int port,
> +			    struct switchdev_brport_flags flags,
> +			    struct netlink_ext_ack *extack)
> +{
> +	struct realtek_smi *smi = ds->priv;
> +	int ret;
> +
> +	if (flags.mask & BR_LEARNING) {
> +		ret = regmap_update_bits(smi->map, RTL8366RB_PORT_LEARNDIS_CTRL,
> +					 BIT(port),
> +					 (flags.val & BR_LEARNING) ? 0 : BIT(port));
> +		if (ret)
> +			return ret;
> +	}
> +
> +	return 0;
> +}
> +
>  static int
>  rtl8366rb_port_bridge_join(struct dsa_switch *ds, int port,
>  			   struct net_device *bridge)
> @@ -1600,6 +1635,8 @@ static const struct dsa_switch_ops rtl8366rb_switch_ops = {
>  	.port_vlan_del = rtl8366_vlan_del,
>  	.port_enable = rtl8366rb_port_enable,
>  	.port_disable = rtl8366rb_port_disable,
> +	.port_pre_bridge_flags = rtl8366rb_port_pre_bridge_flags,
> +	.port_bridge_flags = rtl8366rb_port_bridge_flags,
>  	.port_change_mtu = rtl8366rb_change_mtu,
>  	.port_max_mtu = rtl8366rb_max_mtu,
>  };
> -- 
> 2.31.1
>