[PATCH 0/2] wifi: iwlwifi: fix legacy-rate injection outside 2.4 GHz

[benthecarman via B4 Relay <devnull+benthecarman1.gmail.com@kernel.org>]

Both op modes pass mac80211's legacy rate index for an injected frame
to the driver's rate conversion unchanged. Outside 2.4 GHz that index
points into a bitrate table starting at 6 Mbps, so every injected
legacy rate is shifted down by the four CCK rates: 12 Mbps on 5 GHz
goes out as 5.5 Mbps CCK, which nothing on that band can receive.

I found this bringing up userspace AWDL (OWL) on an AX211: the peer
heard none of our data frames until the rate was remapped. Patch 1
(mvm) was tested on that hardware; patch 2 (mld) is the same fix and
build-tested only, as I have no iwlmld device.

Testing: patch 1 was tested on an Intel AX211 (iwlmvm, firmware
89.123cf747.0) with the same change applied to Ubuntu's 7.0.0-38
kernel, injecting AWDL frames at a radiotap rate of 12 Mbps on channel
44 (5220 MHz). Before, the TX response showed status 0x83 (long retry
limit) and rate_n_flags 0x8002; after, status 0x1, no retries,
rate_n_flags 0x8102, and the peer ACKed every frame. Against
iwlwifi-next both mvm/tx.c and mld/tx.c build without warnings at W=1,
but I could not boot an iwlwifi-next kernel, and patch 2 is untested
at runtime.

The bug was found, and the patches written, with help from an AI
assistant (Claude) during that debugging session; I reviewed and
tested them as described above.

Signed-off-by: benthecarman <benthecarman@live.com>
---
benthecarman (2):
      wifi: iwlwifi: mvm: Fix injected 5 GHz legacy rate
      wifi: iwlwifi: mld: Fix injected 5 GHz legacy rate

 drivers/net/wireless/intel/iwlwifi/mld/tx.c | 11 ++++++++++-
 drivers/net/wireless/intel/iwlwifi/mvm/tx.c |  8 ++++++++
 2 files changed, 18 insertions(+), 1 deletion(-)
---
base-commit: 5d017b30f502e20bfb96ba534b1c36f060a06e98
change-id: 20261009-next-da884048e667

Best regards,
-- 
benthecarman <benthecarman1@gmail.com>