[PATCH 1/2] wifi: ath12k: fix WARN_ON during ath12k_mac_update_vif_chan

[Jeff Johnson]

On 8/2/2023 1:58 AM, Manish Dharanenthiran wrote:
> Fix WARN_ON() from ath12k_mac_update_vif_chan() if vdev is not up.
> Since change_chanctx can be called even before vdev_up.
> 
> Do vdev stop followed by a vdev start in case of vdev is down.
> 
> Tested-on: QCN9274 hw2.0 PCI WLAN.WBE.1.0-02903-QCAHKSWPL_SILICONZ-1

Has this been tested on WCN7850? My understanding is that firmware may 
expect vdev down and then vdev restart

> 
> Signed-off-by: Manish Dharanenthiran <quic_mdharane at quicinc.com>
> ---
>   drivers/net/wireless/ath/ath12k/mac.c | 27 +++++++++++++++++++++------
>   1 file changed, 21 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/net/wireless/ath/ath12k/mac.c b/drivers/net/wireless/ath/ath12k/mac.c
> index 1bb9802ef569..0ab95e138d1d 100644
> --- a/drivers/net/wireless/ath/ath12k/mac.c
> +++ b/drivers/net/wireless/ath/ath12k/mac.c
> @@ -5698,13 +5698,28 @@ ath12k_mac_update_vif_chan(struct ath12k *ar,
>   		if (WARN_ON(!arvif->is_started))
>   			continue;
>   
> -		if (WARN_ON(!arvif->is_up))
> -			continue;
> +		/* Firmware expect vdev_restart only if vdev is up.
> +		 * If vdev is down then it expect vdev_stop->vdev_start.
> +		 */
> +		if (arvif->is_up) {
> +			ret = ath12k_mac_vdev_restart(arvif, &vifs[i].new_ctx->def);
> +			if (ret) {
> +				ath12k_warn(ab, "failed to restart vdev %d: %d\n",
> +					    arvif->vdev_id, ret);
> +				continue;
> +			}
> +		} else {
> +			ret = ath12k_mac_vdev_stop(arvif);
> +			if (ret) {
> +				ath12k_warn(ab, "failed to stop vdev %d: %d\n",
> +					    arvif->vdev_id, ret);
> +				continue;
> +			}
>   
> -		ret = ath12k_mac_vdev_restart(arvif, &vifs[i].new_ctx->def);
> -		if (ret) {
> -			ath12k_warn(ab, "failed to restart vdev %d: %d\n",
> -				    arvif->vdev_id, ret);
> +			ret = ath12k_mac_vdev_start(arvif, &vifs[i].new_ctx->def);
> +			if (ret)
> +				ath12k_warn(ab, "failed to start vdev %d: %d\n",
> +					    arvif->vdev_id, ret);
>   			continue;
>   		}
>