[PATCH] net: ethernet: cpsw: ignore VLAN ID 1

[PATCH] net: ethernet: cpsw: ignore VLAN ID 1

[Felipe Balbi]

CPSW completely hangs if we add, and later remove,
VLAN ID #1. What happens is that after removing
VLAN ID #1, no packets will be received by CPSW
rendering network unusable.

In order to "fix" the issue, we're returning -EINVAL
if anybody tries to add VLAN ID #1. While at that,
also filter out any ID > 4095 because we only have
12 bits for VLAN IDs.

Fixes: 3b72c2f (drivers: net:ethernet: cpsw: add support for VLAN)
Cc: <stable@vger.kernel.org> # v3.9+
Cc: Mugunthan V N <mugunthanvnm@ti.com>
Tested-by: Schuyler Patton <spatton@ti.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
---
 drivers/net/ethernet/ti/cpsw.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/drivers/net/ethernet/ti/cpsw.c b/drivers/net/ethernet/ti/cpsw.c
index e61ee8351272..028bb7f3de65 100644
--- a/drivers/net/ethernet/ti/cpsw.c
+++ b/drivers/net/ethernet/ti/cpsw.c
@@ -1669,6 +1669,13 @@ static int cpsw_ndo_vlan_rx_add_vid(struct net_device *ndev,
 	if (vid == priv->data.default_vlan)
 		return 0;
 
+	/* NOTICE: CPSW does not support VID 1. We should
+	 * also filter out VID > 4095 as we only have 12
+	 * bits for VID entries
+	 */
+	if (vid == 1 || vid >= VLAN_N_VID)
+		return -EINVAL;
+
 	dev_info(priv->dev, "Adding vlanid %d to vlan filter\n", vid);
 	return cpsw_add_vlan_ale_entry(priv, vid);
 }
@@ -1682,6 +1689,13 @@ static int cpsw_ndo_vlan_rx_kill_vid(struct net_device *ndev,
 	if (vid == priv->data.default_vlan)
 		return 0;
 
+	/* NOTICE: CPSW does not support VID 1. We should
+	 * also filter out VID > 4095 as we only have 12
+	 * bits for VID entries
+	 */
+	if (vid == 1 || vid >= VLAN_N_VID)
+		return -EINVAL;
+
 	dev_info(priv->dev, "removing vlanid %d from vlan filter\n", vid);
 	ret = cpsw_ale_del_vlan(priv->ale, vid, 0);
 	if (ret != 0)
-- 
2.2.0

Re: [PATCH] net: ethernet: cpsw: ignore VLAN ID 1

[David Miller]

From: Felipe Balbi <balbi@ti.com>
Date: Tue, 6 Jan 2015 11:43:32 -0600

> CPSW completely hangs if we add, and later remove,
> VLAN ID #1. What happens is that after removing
> VLAN ID #1, no packets will be received by CPSW
> rendering network unusable.
> 
> In order to "fix" the issue, we're returning -EINVAL
> if anybody tries to add VLAN ID #1. While at that,
> also filter out any ID > 4095 because we only have
> 12 bits for VLAN IDs.
> 
> Fixes: 3b72c2f (drivers: net:ethernet: cpsw: add support for VLAN)
> Cc: <stable@vger.kernel.org> # v3.9+
> Cc: Mugunthan V N <mugunthanvnm@ti.com>
> Tested-by: Schuyler Patton <spatton@ti.com>
> Signed-off-by: Felipe Balbi <balbi@ti.com>

You can't just unilaterally make one VLAN ID unusable.

A better way to handle this situation must be found,
and if that means turning off hw VLAN support completely,
that's a much better alternative to this.

I'm not applying this patch, sorry.

Re: [PATCH] net: ethernet: cpsw: ignore VLAN ID 1

[Felipe Balbi]

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Hi,

On Tue, Jan 06, 2015 at 02:13:23PM -0500, David Miller wrote:
> From: Felipe Balbi <balbi@ti.com>
> Date: Tue, 6 Jan 2015 11:43:32 -0600
> 
> > CPSW completely hangs if we add, and later remove,
> > VLAN ID #1. What happens is that after removing
> > VLAN ID #1, no packets will be received by CPSW
> > rendering network unusable.
> > 
> > In order to "fix" the issue, we're returning -EINVAL
> > if anybody tries to add VLAN ID #1. While at that,
> > also filter out any ID > 4095 because we only have
> > 12 bits for VLAN IDs.
> > 
> > Fixes: 3b72c2f (drivers: net:ethernet: cpsw: add support for VLAN)
> > Cc: <stable@vger.kernel.org> # v3.9+
> > Cc: Mugunthan V N <mugunthanvnm@ti.com>
> > Tested-by: Schuyler Patton <spatton@ti.com>
> > Signed-off-by: Felipe Balbi <balbi@ti.com>
> 
> You can't just unilaterally make one VLAN ID unusable.
> 
> A better way to handle this situation must be found,
> and if that means turning off hw VLAN support completely,
> that's a much better alternative to this.
> 
> I'm not applying this patch, sorry.

All other IDs work alright, it's just ID 1 which seems to be quirky. In
fact when trying to add VLAN ID 1, vconfig itself dumps out a warning
that VLAN ID 1 doesn't work on most switches.

What you're saying here is that you prefer to drop a feature that works
for all other 1023 IDs because 1 ID is quirky. Sounds like overkill
to me.

-- 
balbi

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Re: [PATCH] net: ethernet: cpsw: ignore VLAN ID 1

[David Miller]

From: Felipe Balbi <balbi@ti.com>
Date: Tue, 6 Jan 2015 14:31:19 -0600

> What you're saying here is that you prefer to drop a feature that works
> for all other 1023 IDs because 1 ID is quirky. Sounds like overkill
> to me.

The other option is to software fallback only for VLAN 1.

Re: [PATCH] net: ethernet: cpsw: ignore VLAN ID 1

[Felipe Balbi]

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Hi,

On Tue, Jan 06, 2015 at 04:59:11PM -0500, David Miller wrote:
> From: Felipe Balbi <balbi@ti.com>
> Date: Tue, 6 Jan 2015 14:31:19 -0600
> 
> > What you're saying here is that you prefer to drop a feature that works
> > for all other 1023 IDs because 1 ID is quirky. Sounds like overkill
> > to me.
> 
> The other option is to software fallback only for VLAN 1.

now we're talking. Keep in mind, however, that this IP runs on mere
single-core cortex A8 and single-core cortex A9 devices which already
have somewhat of a hard-time keeping up with the non-accelerated
checksum calculations. But fair enough, if that's the way to go, it is
the way to go.

cheers

-- 
balbi

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