Re: [PATCH 5.10 52/96] net: dsa: microchip: ksz8795: Fix VLAN filtering

[Ben Hutchings <ben.hutchings@essensium.com>]

On Mon, Aug 16, 2021 at 03:02:02PM +0200, Greg Kroah-Hartman wrote:
> From: Ben Hutchings <ben.hutchings@mind.be>
> 
> [ Upstream commit 164844135a3f215d3018ee9d6875336beb942413 ]

This will probably work on its own, but it was tested as part of a
series of changes to VLAN handling in the driver.  Since I initially
developed and tested that on top of 5.10-stable, I would prefer to
send you the complete series to apply together.

Ben.

> Currently ksz8_port_vlan_filtering() sets or clears the VLAN Enable
> hardware flag.  That controls discarding of packets with a VID that
> has not been enabled for any port on the switch.
> 
> Since it is a global flag, set the dsa_switch::vlan_filtering_is_global
> flag so that the DSA core understands this can't be controlled per
> port.
> 
> When VLAN filtering is enabled, the switch should also discard packets
> with a VID that's not enabled on the ingress port.  Set or clear each
> external port's VLAN Ingress Filter flag in ksz8_port_vlan_filtering()
> to make that happen.
> 
> Fixes: e66f840c08a2 ("net: dsa: ksz: Add Microchip KSZ8795 DSA driver")
> Signed-off-by: Ben Hutchings <ben.hutchings@mind.be>
> Signed-off-by: David S. Miller <davem@davemloft.net>
> Signed-off-by: Sasha Levin <sashal@kernel.org>
> ---
>  drivers/net/dsa/microchip/ksz8795.c | 11 +++++++++++
>  1 file changed, 11 insertions(+)
> 
> diff --git a/drivers/net/dsa/microchip/ksz8795.c b/drivers/net/dsa/microchip/ksz8795.c
> index 1e101ab56cea..108a14db1f1a 100644
> --- a/drivers/net/dsa/microchip/ksz8795.c
> +++ b/drivers/net/dsa/microchip/ksz8795.c
> @@ -790,8 +790,14 @@ static int ksz8795_port_vlan_filtering(struct dsa_switch *ds, int port,
>  	if (switchdev_trans_ph_prepare(trans))
>  		return 0;
>  
> +	/* Discard packets with VID not enabled on the switch */
>  	ksz_cfg(dev, S_MIRROR_CTRL, SW_VLAN_ENABLE, flag);
>  
> +	/* Discard packets with VID not enabled on the ingress port */
> +	for (port = 0; port < dev->phy_port_cnt; ++port)
> +		ksz_port_cfg(dev, port, REG_PORT_CTRL_2, PORT_INGRESS_FILTER,
> +			     flag);
> +
>  	return 0;
>  }
>  
> @@ -1266,6 +1272,11 @@ static int ksz8795_switch_init(struct ksz_device *dev)
>  	/* set the real number of ports */
>  	dev->ds->num_ports = dev->port_cnt + 1;
>  
> +	/* VLAN filtering is partly controlled by the global VLAN
> +	 * Enable flag
> +	 */
> +	dev->ds->vlan_filtering_is_global = true;
> +
>  	return 0;
>  }
>  
> -- 
> 2.30.2
> 
> 
> 

-- 
Ben Hutchings · Senior Embedded Software Engineer, Essensium-Mind · mind.be