Subject: Re: [PATCH net-next 2/2] net: dsa: lan9303: Learn addresses on CPU port when bridged

From: Andrew Lunn <[email-masked]>
Date: Tue, 24 Oct 2017 18:33:34 +0200

On Tue, Oct 24, 2017 at 11:35:15AM +0200, Egil Hjelmeland wrote:
> When CPU transmit directly to port using tag, the LAN9303 does not
> learn MAC addresses received on the CPU port into the ALR.
> ALR learning is performed only when transmitting using ALR lookup.
> 
> Solution:
> If the two external ports are bridged and the packet is not STP BPDU,
> then use ALR lookup to allow ALR learning on CPU port.
> Otherwise transmit directly to port with STP state override.
> 
> Signed-off-by: Egil Hjelmeland <[email-masked]>
> ---
>  net/dsa/tag_lan9303.c | 23 ++++++++++++++++++++++-
>  1 file changed, 22 insertions(+), 1 deletion(-)
> 
> diff --git a/net/dsa/tag_lan9303.c b/net/dsa/tag_lan9303.c
> index 57519597c6fc..174721293a34 100644
> --- a/net/dsa/tag_lan9303.c
> +++ b/net/dsa/tag_lan9303.c
> @@ -12,6 +12,7 @@
>   *
>   */
>  #include <linux/etherdevice.h>
> +#include <linux/lan9303.h>
>  #include <linux/list.h>
>  #include <linux/slab.h>
>  
> @@ -39,6 +40,23 @@
>   */
>  
>  #define LAN9303_TAG_LEN 4
> +# define LAN9303_TAG_TX_USE_ALR BIT(3)
> +# define LAN9303_TAG_TX_STP_OVERRIDE BIT(4)
> +#define eth_stp_addr eth_reserved_addr_base
> +
> +/* Decide whether to transmit using ALR lookup, or transmit directly to
> + * port using tag. ALR learning is performed only when using ALR lookup.
> + * If the two external ports are bridged and the packet is not STP BPDU,
> + * then use ALR lookup to allow ALR learning on CPU port.
> + * Otherwise transmit directly to port with STP state override.
> + * See also: lan9303_separate_ports() and lan9303.pdf 6.4.10.1
> + */
> +static inline int lan9303_tx_use_arl(struct dsa_port *dp, u8 *dest_addr)

Hi Egil

There is no need for the inline. The compiler will do that anyway, for
a function like this.

    Andrew