wifi: ath12k: Fix legacy rate mapping for monitor mode capture

The current implementation incorrectly reports legacy CCK and OFDM rates
in monitor mode radiotap headers. The rate field displays wrong values,
for example showing 11 Mbps when the actual rate is 1 Mbps. This occurs
because the HAL layer uses a unified enum for both CCK and OFDM rates
without distinguishing between long/short preamble variants and proper
rate mapping to hardware rate indices.

The root cause is threefold:

1. The hal_rx_legacy_rate enum conflates CCK and OFDM rates into a
   single enumeration, making it impossible to differentiate between
   802.11b CCK rates (with long/short preamble variants) and 802.11a/g
   OFDM rates.

2. The L-SIG-B parsing function maps hardware rate values to the wrong
   enum values. For CCK rates, it incorrectly combines long and short
   preamble cases (e.g., cases 2 and 5 both map to 2 Mbps), losing
   preamble information critical for proper rate identification.

3. The mac layer's rate-to-index conversion function does not properly
   handle the precedence between long preamble, short preamble, and
   OFDM rates when matching hardware rate values.

Split the hal_rx_legacy_rate enum into two separate enumerations:
hal_rx_legacy_rate for CCK rates with explicit long preamble (LP) and
short preamble (SP) variants, and hal_rx_legacy_rates_ofdm for OFDM
rates. This separation allows proper identification of rate types and
preamble modes.

Introduce a new mapping ath12k_wifi7_hal_mon_map_legacy_rate_to_hw_rate()
that converts HAL CCK rate enums to hardware rate indices defined in
ath12k_hw_rate_cck. This ensures the rate field in ppdu_info contains
the correct hardware rate index that matches the mac layer's expectations.

Update the L-SIG-B parsing to map each hardware rate value (1-7) to its
corresponding CCK rate enum with proper preamble designation:
- Cases 1-4: Long preamble (1, 2, 5.5, 11 Mbps)
- Cases 5-7: Short preamble (2, 5.5, 11 Mbps)

Update the L-SIG-A parsing to use the new OFDM-specific enum values,
maintaining the existing rate mapping for 802.11a/g OFDM rates.

Refactor the mac layer's ath12k_mac_hw_rate_to_idx() function to
implement proper matching precedence:
1. First match OFDM rates using the IEEE80211_RATE_MANDATORY_A flag
2. Then match CCK short preamble rates
3. Finally match CCK long preamble rates as fallback

Add helper macros ATH12K_MAC_RATE_A_M and ATH12K_MAC_RATE_B to improve
readability of the rate table initialization and ensure the mandatory
flag is set for OFDM rates.

This fix ensures monitor mode captures display accurate rate information
in the radiotap header, correctly distinguishing between 1 Mbps and
11 Mbps, and properly identifying preamble types for CCK rates.

Tested-on: QCN9274 hw2.0 PCI WLAN.WBE.1.6-01181-QCAHKSWPL_SILICONZ-1

Fixes: d889913205cf ("wifi: ath12k: driver for Qualcomm Wi-Fi 7 devices")
Signed-off-by: P Praneesh <praneesh.p@oss.qualcomm.com>
Signed-off-by: Thiraviyam Mariyappan <thiraviyam.mariyappan@oss.qualcomm.com>
Reviewed-by: Baochen Qiang <baochen.qiang@oss.qualcomm.com>
Reviewed-by: Vasanthakumar Thiagarajan <vasanthakumar.thiagarajan@oss.qualcomm.com>
Link: https://patch.msgid.link/20260209054924.2713072-1-thiraviyam.mariyappan@oss.qualcomm.com
Signed-off-by: Jeff Johnson <jeff.johnson@oss.qualcomm.com>

0 files changed, 0 insertions, 0 deletions