[PATCH ath-current] wifi: ath12k: don't advertise EHT-MCS15 to firmware unless we support it

[Vasanthakumar Thiagarajan]

On 29-10-2026 07:48, Baochen Qiang wrote:
> ath12k_peer_assoc_h_eht() copies the peer's EHT PHY capabilities into
> the WMI peer assoc command as is, including the EHT-MCS15 support bits.
> Firmware rate control enables EHT-MCS15 for TX whenever those bits are
> set, without checking whether the local PHY supports MCS15.
> 
> Currently WCN7850 firmware does not support EHT-MCS15 for TX and does
> not advertise it in its own EHT PHY capabilities. When connected to an
> AP that advertises MCS15 support, rate control may still select
> EHT-MCS15, and every PPDU at that rate is aborted by the PHY before it
> goes on the air. TX then stops for minutes while the association stays
> up, and frames sit in the queue until the firmware releases them as aged.
> 
> Keep only the peer's MCS15 support bits that we also support ourselves
> to fix it. Chips that support MCS15 are not affected.
> 
> Tested-on: WCN7850 hw2.0 PCI WLAN.HMT.1.1.c7-00108-QCAHMTSWPL_V1.0_V2.0_SILICONZ_UPSTREAM-3
> 
> Fixes: 17bbb8aa74fd ("wifi: ath12k: prepare EHT peer assoc parameters")
> Reported-by: Vladimir Petrzhikovskii <vladimir at dfb.sh>
> Closes: https://bugzilla.kernel.org/show_bug.cgi?id=222136
> Tested-by: Vladimir Petrzhikovskii <vladimir at dfb.sh>
> Signed-off-by: Baochen Qiang <baochen.qiang at oss.qualcomm.com>

Reviewed-by: Vasanthakumar Thiagarajan <vasanthakumar.thiagarajan at oss.qualcomm.com>