Files
openwrt/target
Jan Leon a34ff932fa qualcommax: qca_ppe: fix BPDU trapping and CPU transmission
The STP APP_CTRL rule uses 0x93fc for its third word. CMD occupies
bits 16:15 of that word, so this selects DROP (1), not the intended
REDIRECT_TO_CPU (3). Incoming BPDUs never reach the bridge protocol
implementation even though ordinary traffic continues to work.

Correcting only CMD exposes another issue: the 0x7f ingress port mask
includes CPU port 0. CPU-originated BPDUs are then trapped back to the
CPU rather than transmitted to the selected external port. Exclude
the CPU and SoC-specific loopback ports, deriving the remaining mask
from the port count. Use named fields for the third word so the action
and port selection are explicit.

On an AX3600/IPQ8074 running 6.18.44, register readback confirmed the
original rule. A guarded runtime test of 0x193fc restored BPDU reception
but captured locally generated BPDUs on the CPU RX path. With 0x193f4,
those RX reflections disappeared and the adjacent switch received
bridge protocol traffic again. Reapplying that value automatically
after a reboot established RSTP with the upstream root. The patched
driver also builds against the matching aarch64 kernel SDK.

IPQ6018's generated mask was checked, but not tested on hardware.

Fixes: 142104bb90 ("qualcommax: add PPE driver")
Assisted-by: OpenAI Codex
Signed-off-by: Jan Leon <Jan.gaschler@gmail.com>
Link: https://github.com/openwrt/openwrt/pull/25063
Signed-off-by: Robert Marko <robimarko@gmail.com>
2026-09-07 15:59:08 +02:00
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