[PATCH v2 0/2] DSA tagging mismatches

The second patch is a fix, which should be applied to -rc. It is
possible to get a DSA configuration which does not work. The patch
stops this happening.

The first patch detects this situation, and errors out the probe of
DSA, making it more obvious something is wrong. It is not required to
apply it -rc.


v2 fixes the use case pointed out by Florian, that a switch driver
may use DSA_TAG_PROTO_NONE which the patch did not correctly handle.

Andrew Lunn (2):
  net: dsa: Error out on tagging protocol mismatches
  dsa: mv88e6171: Fix tagging protocol/Kconfig

 drivers/net/dsa/mv88e6171.c | 2 +-
 net/dsa/dsa.c               | 5 ++++-
 2 files changed, 5 insertions(+), 2 deletions(-)

-- 
2.1.1

The mv88e6171 can support two different tagging protocols, DSA and
EDSA. The switch driver structure only allows one protocol to be
enumerated, and DSA was chosen. However the Kconfig entry ensures the
EDSA tagging code is built. With a minimal configuration, we then end
up with a mismatch. The probe is successful, EDSA tagging is used, but
the switch is configured for DSA, resulting in mangled packets.

Change the switch driver structure to enumerate EDSA, fixing the
mismatch.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Fixes: 42f272539487 ("net: DSA: Marvell mv88e6171 switch driver")
---
 drivers/net/dsa/mv88e6171.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/dsa/mv88e6171.c b/drivers/net/dsa/mv88e6171.c
index 1020a7af67cf..78d8e876f3aa 100644
--- a/drivers/net/dsa/mv88e6171.c
+++ b/drivers/net/dsa/mv88e6171.c

@@ -395,7 +395,7 @@ static int mv88e6171_get_sset_count(struct dsa_switch *ds)
 }
 
 struct dsa_switch_driver mv88e6171_switch_driver = {
-	.tag_protocol		= DSA_TAG_PROTO_DSA,
+	.tag_protocol		= DSA_TAG_PROTO_EDSA,
 	.priv_size		= sizeof(struct mv88e6xxx_priv_state),
 	.probe			= mv88e6171_probe,
 	.setup			= mv88e6171_setup,

-- 
2.1.1

On 10/24/2014 02:44 PM, Andrew Lunn wrote:

The mv88e6171 can support two different tagging protocols, DSA and
EDSA. The switch driver structure only allows one protocol to be
enumerated, and DSA was chosen. However the Kconfig entry ensures the
EDSA tagging code is built. With a minimal configuration, we then end
up with a mismatch. The probe is successful, EDSA tagging is used, but
the switch is configured for DSA, resulting in mangled packets.

Change the switch driver structure to enumerate EDSA, fixing the
mismatch.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Fixes: 42f272539487 ("net: DSA: Marvell mv88e6171 switch driver")

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

If there is a mismatch between enabled tagging protocols and the
protocol the switch supports, error out, rather than continue with a
situation which is unlikely to work.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
cc: alexander.h.duyck@intel.com
---

v2: Handle the use case of DSA_TAG_PROTO_NONE

 net/dsa/dsa.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/net/dsa/dsa.c b/net/dsa/dsa.c
index 22f34cf4cb27..6317b41c99b0 100644
--- a/net/dsa/dsa.c
+++ b/net/dsa/dsa.c

@@ -174,8 +174,11 @@ dsa_switch_setup(struct dsa_switch_tree *dst, int index,
 			dst->rcv = brcm_netdev_ops.rcv;
 			break;
 #endif
-		default:
+		case DSA_TAG_PROTO_NONE:
 			break;
+		default:
+			ret = -ENOPROTOOPT;
+			goto out;
 		}
 
 		dst->tag_protocol = drv->tag_protocol;

-- 
2.1.1

On 10/24/2014 02:44 PM, Andrew Lunn wrote:

If there is a mismatch between enabled tagging protocols and the
protocol the switch supports, error out, rather than continue with a
situation which is unlikely to work.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>

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

From: Andrew Lunn <andrew@lunn.ch>
Date: Fri, 24 Oct 2014 23:44:03 +0200

The second patch is a fix, which should be applied to -rc. It is
possible to get a DSA configuration which does not work. The patch
stops this happening.

The first patch detects this situation, and errors out the probe of
DSA, making it more obvious something is wrong. It is not required to
apply it -rc.

v2 fixes the use case pointed out by Florian, that a switch driver
may use DSA_TAG_PROTO_NONE which the patch did not correctly handle.

Series applied, thanks Andrew.