[PATCH net-next] net: dsa: mv88e6xxx: fix vlan setup

[PATCH net-next] net: dsa: mv88e6xxx: fix vlan setup

[Russell King]

DSA assumes that a bridge which has vlan filtering disabled is not
vlan aware, and ignores all vlan configuration. However, the kernel
software bridge code allows configuration in this state.

This causes the kernel's idea of the bridge vlan state and the
hardware state to disagree, so "bridge vlan show" indicates a correct
configuration but the hardware lacks all configuration. Even worse,
enabling vlan filtering on a DSA bridge immediately blocks all traffic
which, given the output of "bridge vlan show", is very confusing.

Allow the VLAN configuration to be updated on Marvell DSA bridges,
otherwise we end up cutting all traffic when enabling vlan filtering.

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
---
This is the revised version of the patch that has been waiting a long
time to fix this issue on the Marvell DSA switches.

 drivers/net/dsa/mv88e6xxx/chip.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/net/dsa/mv88e6xxx/chip.c b/drivers/net/dsa/mv88e6xxx/chip.c
index bd297ae7cf9e..72340c17f099 100644
--- a/drivers/net/dsa/mv88e6xxx/chip.c
+++ b/drivers/net/dsa/mv88e6xxx/chip.c
@@ -2851,6 +2851,7 @@ static int mv88e6xxx_setup(struct dsa_switch *ds)
 
 	chip->ds = ds;
 	ds->slave_mii_bus = mv88e6xxx_default_mdio_bus(chip);
+	ds->configure_vlan_while_not_filtering = true;
 
 	mv88e6xxx_reg_lock(chip);
 
-- 
2.20.1

Re: [PATCH net-next] net: dsa: mv88e6xxx: fix vlan setup

[Florian Fainelli]

On 10/29/2020 9:09 AM, Russell King wrote:
> DSA assumes that a bridge which has vlan filtering disabled is not
> vlan aware, and ignores all vlan configuration. However, the kernel
> software bridge code allows configuration in this state.
> 
> This causes the kernel's idea of the bridge vlan state and the
> hardware state to disagree, so "bridge vlan show" indicates a correct
> configuration but the hardware lacks all configuration. Even worse,
> enabling vlan filtering on a DSA bridge immediately blocks all traffic
> which, given the output of "bridge vlan show", is very confusing.
> 
> Allow the VLAN configuration to be updated on Marvell DSA bridges,
> otherwise we end up cutting all traffic when enabling vlan filtering.
> 
> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>

Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
-- 
Florian

Re: [PATCH net-next] net: dsa: mv88e6xxx: fix vlan setup

[Vladimir Oltean]

On Thu, Oct 29, 2020 at 04:09:03PM +0000, Russell King wrote:
> DSA assumes that a bridge which has vlan filtering disabled is not
> vlan aware, and ignores all vlan configuration. However, the kernel
> software bridge code allows configuration in this state.
> 
> This causes the kernel's idea of the bridge vlan state and the
> hardware state to disagree, so "bridge vlan show" indicates a correct
> configuration but the hardware lacks all configuration. Even worse,
> enabling vlan filtering on a DSA bridge immediately blocks all traffic
> which, given the output of "bridge vlan show", is very confusing.
> 
> Allow the VLAN configuration to be updated on Marvell DSA bridges,
> otherwise we end up cutting all traffic when enabling vlan filtering.
> 
> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
> ---

Tested-by: Vladimir Oltean <olteanv@gmail.com>

> This is the revised version of the patch that has been waiting a long
> time to fix this issue on the Marvell DSA switches.
> 
>  drivers/net/dsa/mv88e6xxx/chip.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/net/dsa/mv88e6xxx/chip.c b/drivers/net/dsa/mv88e6xxx/chip.c
> index bd297ae7cf9e..72340c17f099 100644
> --- a/drivers/net/dsa/mv88e6xxx/chip.c
> +++ b/drivers/net/dsa/mv88e6xxx/chip.c
> @@ -2851,6 +2851,7 @@ static int mv88e6xxx_setup(struct dsa_switch *ds)
>  
>  	chip->ds = ds;
>  	ds->slave_mii_bus = mv88e6xxx_default_mdio_bus(chip);
> +	ds->configure_vlan_while_not_filtering = true;
>  
>  	mv88e6xxx_reg_lock(chip);
>  
> -- 
> 2.20.1
> 

Re: [PATCH net-next] net: dsa: mv88e6xxx: fix vlan setup

[Jakub Kicinski]

On Thu, 29 Oct 2020 16:09:03 +0000 Russell King wrote:
> DSA assumes that a bridge which has vlan filtering disabled is not
> vlan aware, and ignores all vlan configuration. However, the kernel
> software bridge code allows configuration in this state.
> 
> This causes the kernel's idea of the bridge vlan state and the
> hardware state to disagree, so "bridge vlan show" indicates a correct
> configuration but the hardware lacks all configuration. Even worse,
> enabling vlan filtering on a DSA bridge immediately blocks all traffic
> which, given the output of "bridge vlan show", is very confusing.
> 
> Allow the VLAN configuration to be updated on Marvell DSA bridges,
> otherwise we end up cutting all traffic when enabling vlan filtering.
> 
> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>

Applied, thanks!