Re: [PATCH ath-next v2] wifi: ath12k: Prevent incorrect vif chanctx switch when handling multi-radio contexts

[Rameshkumar Sundaram <rameshkumar.sundaram@oss.qualcomm.com>]

On 5/22/2026 2:48 PM, Maharaja Kennadyrajan wrote:
> From: Aditya Kumar Singh <aditya.kumar.singh@oss.qualcomm.com>
> 
> When multiple links switch channel contexts around the same time, mac80211
> may complete CSA for several links together and invoke
> ath12k_mac_op_switch_vif_chanctx() with an array of vifs spanning more than
> one underlying radio in a single-wiphy configuration.
> 
> The driver currently assumes that all entries in the vifs array belong to the
> same radio and derives the radio context from the first element. On multi-radio
> hardware, this can lead to incorrect vdev selection/updates and may corrupt
> driver state when the number of vifs exceeds what a single radio supports.
> 
> Fix this by validating each vif's switch request and then processing vifs
> grouped by their associated radio. For each vif, ensure the band does not
> change across the switch and that both old/new channel contexts resolve to a
> valid ath12k device. Reject attempts to move a vif between radios (not
> supported for now) and return -EOPNOTSUPP to upper layers.
> 
> Then, iterate through the input vifs, collect all unprocessed entries that map
> to the same radio, and invoke ath12k_mac_update_vif_chan() separately for each
> radio group. This removes any reliance on mac80211 providing the array grouped
> by radio or sharing old_ctx pointers across vifs.
> 
> Tested-on: QCN9274 hw2.0 PCI WLAN.WBE.1.5-01651-QCAHKSWPL_SILICONZ-1
> 
> Signed-off-by: Aditya Kumar Singh <aditya.kumar.singh@oss.qualcomm.com>
> Co-developed-by: Maharaja Kennadyrajan <maharaja.kennadyrajan@oss.qualcomm.com>
> Signed-off-by: Maharaja Kennadyrajan <maharaja.kennadyrajan@oss.qualcomm.com>
Reviewed-by: Rameshkumar Sundaram <rameshkumar.sundaram@oss.qualcomm.com>