FAILED: patch "[PATCH] net: dsa: microchip: fix bridging with more than two member" failed to apply to 5.16-stable tree

Quoted 4 lines

The patch below does not apply to the 5.16-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

Quoted 2 lines

------------------ original commit in Linus's tree ------------------ From 3d00827a90db6f79abc7cdc553887f89a2e0a184 Mon Sep 17 00:00:00 2001

Quoted 4 lines · gregkh@linuxfoundation wrote:

Quoted 4 lines

The patch below does not apply to the 5.16-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

...

Quoted 2 lines

Quoted 2 lines

------------------ original commit in Linus's tree ------------------

Quoted 1 line

From 3d00827a90db6f79abc7cdc553887f89a2e0a184 Mon Sep 17 00:00:00 2001

Hi Greg,

That's strange - it applies just fine without errors here:

--- snip ---

$ git log --oneline -n 1
f40e0f7a433b (HEAD -> linux-5.16.y, tag: v5.16.11, stable/linux-5.16.y) Linux 5.16.11
$ git cherry-pick -x 3d00827a90db6f79abc7cdc553887f89a2e0a184
[linux-5.16.y e1e17aca71a0] net: dsa: microchip: fix bridging with more than two member ports
 Date: Fri Feb 18 11:27:01 2022 +0000
 1 file changed, 23 insertions(+), 3 deletions(-)
--- snip ---

So I'm not sure what's needed for backporting?

Quoted 3 lines

Quoted 3 lines

The patch below does not apply to the 5.16-stable tree. ------------------ original commit in Linus's tree ------------------

Quoted 1 line

From 3d00827a90db6f79abc7cdc553887f89a2e0a184 Mon Sep 17 00:00:00 2001

Quoted 1 line

That's strange - it applies just fine without errors here:

Try building it :)

Quoted 4 lines · gregkh@linuxfoundation wrote:

Quoted 4 lines

The patch below does not apply to the 5.16-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

...

Quoted 2 lines

Quoted 2 lines

------------------ original commit in Linus's tree ------------------

Quoted 1 line

From 3d00827a90db6f79abc7cdc553887f89a2e0a184 Mon Sep 17 00:00:00 2001

Hi Greg,

That's strange - it applies just fine without errors here:

--- snip ---

$ git log --oneline -n 1
f40e0f7a433b (HEAD -> linux-5.16.y, tag: v5.16.11, stable/linux-5.16.y) Linux 5.16.11
$ git cherry-pick -x 3d00827a90db6f79abc7cdc553887f89a2e0a184
[linux-5.16.y e1e17aca71a0] net: dsa: microchip: fix bridging with more than two member ports
 Date: Fri Feb 18 11:27:01 2022 +0000
 1 file changed, 23 insertions(+), 3 deletions(-)
--- snip ---

So I'm not sure what's needed for backporting?

Commit b3612ccdf284 ("net: dsa: microchip: implement multi-bridge support") plugged a packet leak between ports that were members of different bridges. Unfortunately, this broke another use case, namely that of more than two ports that are members of the same bridge.

After that commit, when a port is added to a bridge, hardware bridging between other member ports of that bridge will be cleared, preventing packet exchange between them.

Fix by ensuring that the Port VLAN Membership bitmap includes any existing ports in the bridge, not just the port being added.

Upstream commit 3d00827a90db6f79abc7cdc553887f89a2e0a184, backported to 5.16.

Fixes b3612ccdf284 ("net: dsa: microchip: implement multi-bridge support")

Signed-off-by Svenning Sørensen <[email protected]>

Tested-by Oleksij Rempel <[email protected]>

Signed-off-by David S. Miller <[email protected]>

---
 drivers/net/dsa/microchip/ksz_common.c | 26 +++++++++++++++++++++++---
 1 file changed, 23 insertions(+), 3 deletions(-)

drivers/net/dsa/microchip/ksz_common.c +23 -4

index 8a04302018dc..7ab9ab58de65 100644
@@ -26,7 +26,7 @@ void ksz_update_port_member(struct ksz_device *dev, int port)
        struct dsa_switch *ds = dev->ds;
        u8 port_member = 0, cpu_port;
        const struct dsa_port *dp;
-       int i;
+       int i, j;
 
        if (!dsa_is_user_port(ds, port))
                return;

@@ -45,13 +45,33 @@ void ksz_update_port_member(struct ksz_device *dev, int port)
                        continue;
                if (!dp->bridge_dev || dp->bridge_dev != other_dp->bridge_dev)
                        continue;
+               if (other_p->stp_state != BR_STATE_FORWARDING)
+                       continue;
 
-               if (other_p->stp_state == BR_STATE_FORWARDING &&
-                   p->stp_state == BR_STATE_FORWARDING) {
+               if (p->stp_state == BR_STATE_FORWARDING) {
                        val |= BIT(port);
                        port_member |= BIT(i);
                }
 
+               /* Retain port [i]'s relationship to other ports than [port] */
+               for (j = 0; j < ds->num_ports; j++) {
+                       const struct dsa_port *third_dp;
+                       struct ksz_port *third_p;
+
+                       if (j == i)
+                               continue;
+                       if (j == port)
+                               continue;
+                       if (!dsa_is_user_port(ds, j))
+                               continue;
+                       third_p = &dev->ports[j];
+                       if (third_p->stp_state != BR_STATE_FORWARDING)
+                               continue;
+                       third_dp = dsa_to_port(ds, j);
+                       if (third_dp->bridge_dev == dp->bridge_dev)
+                               val |= BIT(j);
+               }
+
                dev->dev_ops->cfg_port_member(dev, i, val | cpu_port);
        }
 
--

2.20.1