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authorVladimir Oltean <vladimir.oltean@nxp.com>2024-08-15 03:07:05 +0300
committerDavid S. Miller <davem@davemloft.net>2024-08-16 09:59:32 +0100
commit93e4649efa964201c73b0a03c35c04a0d6fc809f (patch)
treeba267f87d666183300e35eab451a79088d11f3e6 /include
parentc5e12ac3beb0dd3a718296b2d8af5528e9ab728e (diff)
net: dsa: provide a software untagging function on RX for VLAN-aware bridges
Through code analysis, I realized that the ds->untag_bridge_pvid logic is contradictory - see the newly added FIXME above the kernel-doc for dsa_software_untag_vlan_unaware_bridge(). Moreover, for the Felix driver, I need something very similar, but which is actually _not_ contradictory: untag the bridge PVID on RX, but for VLAN-aware bridges. The existing logic does it for VLAN-unaware bridges. Since I don't want to change the functionality of drivers which were supposedly properly tested with the ds->untag_bridge_pvid flag, I have introduced a new one: ds->untag_vlan_aware_bridge_pvid, and I have refactored the DSA reception code into a common path for both flags. TODO: both flags should be unified under a single ds->software_vlan_untag, which users of both current flags should set. This is not something that can be carried out right away. It needs very careful examination of all drivers which make use of this functionality, since some of them actually get this wrong in the first place. For example, commit 9130c2d30c17 ("net: dsa: microchip: ksz8795: Use software untagging on CPU port") uses this in a driver which has ds->configure_vlan_while_not_filtering = true. The latter mechanism has been known for many years to be broken by design: https://lore.kernel.org/netdev/CABumfLzJmXDN_W-8Z=p9KyKUVi_HhS7o_poBkeKHS2BkAiyYpw@mail.gmail.com/ and we have the situation of 2 bugs canceling each other. There is no private VLAN, and the port follows the PVID of the VLAN-unaware bridge. So, it's kinda ok for that driver to use the ds->untag_bridge_pvid mechanism, in a broken way. Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include')
-rw-r--r--include/net/dsa.h16
1 files changed, 10 insertions, 6 deletions
diff --git a/include/net/dsa.h b/include/net/dsa.h
index b06f97ae3da1..d7a6c2930277 100644
--- a/include/net/dsa.h
+++ b/include/net/dsa.h
@@ -403,14 +403,18 @@ struct dsa_switch {
*/
u32 configure_vlan_while_not_filtering:1;
- /* If the switch driver always programs the CPU port as egress tagged
- * despite the VLAN configuration indicating otherwise, then setting
- * @untag_bridge_pvid will force the DSA receive path to pop the
- * bridge's default_pvid VLAN tagged frames to offer a consistent
- * behavior between a vlan_filtering=0 and vlan_filtering=1 bridge
- * device.
+ /* Pop the default_pvid of VLAN-unaware bridge ports from tagged frames.
+ * DEPRECATED: Do NOT set this field in new drivers. Instead look at
+ * the dsa_software_vlan_untag() comments.
*/
u32 untag_bridge_pvid:1;
+ /* Pop the default_pvid of VLAN-aware bridge ports from tagged frames.
+ * Useful if the switch cannot preserve the VLAN tag as seen on the
+ * wire for user port ingress, and chooses to send all frames as
+ * VLAN-tagged to the CPU, including those which were originally
+ * untagged.
+ */
+ u32 untag_vlan_aware_bridge_pvid:1;
/* Let DSA manage the FDB entries towards the
* CPU, based on the software bridge database.