wifi: ath12k: don't wait when there is no vdev started

JIRA: https://issues.redhat.com/browse/RHEL-122256

commit ad5e917
Author: Baochen Qiang <quic_bqiang@quicinc.com>
Date:   Thu Jun 12 09:31:52 2025 +0800

    wifi: ath12k: don't wait when there is no vdev started
    
    For WMI_REQUEST_VDEV_STAT request, firmware might split response into
    multiple events dut to buffer limit, hence currently in
    ath12k_wmi_fw_stats_process() host waits until all events received. In
    case there is no vdev started, this results in that below condition
    would never get satisfied
    
            ((++ar->fw_stats.num_vdev_recvd) == total_vdevs_started)
    
    consequently the requestor would be blocked until time out.
    
    The same applies to WMI_REQUEST_BCN_STAT request as well due to:
    
            ((++ar->fw_stats.num_bcn_recvd) == ar->num_started_vdevs)
    
    Change to check the number of started vdev first: if it is zero, finish
    directly; if not, follow the old way.
    
    Tested-on: WCN7850 hw2.0 PCI WLAN.HMT.1.1.c5-00284.1-QCAHMTSWPL_V1.0_V2.0_SILICONZ-3
    Tested-on: QCN9274 hw2.0 WLAN.WBE.1.5-01651-QCAHKSWPL_SILICONZ-1
    
    Fixes: e367c92 ("wifi: ath12k: Request vdev stats from firmware")
    Signed-off-by: Baochen Qiang <quic_bqiang@quicinc.com>
    Link: https://patch.msgid.link/20250612-ath12k-fw-fixes-v1-4-12f594f3b857@quicinc.com
    Signed-off-by: Jeff Johnson <jeff.johnson@oss.qualcomm.com>

Signed-off-by: Jose Ignacio Tornos Martinez <jtornosm@redhat.com>

Author: jtornosm

drivers/net/wireless/ath/ath12k/wmi.c

@@ -8165,7 +8165,7 @@ static void ath12k_wmi_fw_stats_process(struct ath12k *ar,
 {
 	struct ath12k_base *ab = ar->ab;
 	struct ath12k_pdev *pdev;
-	bool is_end;
+	bool is_end = true;
 	size_t total_vdevs_started = 0;
 	int i;
 
@@ -8185,7 +8185,9 @@ static void ath12k_wmi_fw_stats_process(struct ath12k *ar,
 		}
 		rcu_read_unlock();
 
-		is_end = ((++ar->fw_stats.num_vdev_recvd) == total_vdevs_started);
+		if (total_vdevs_started)
+			is_end = ((++ar->fw_stats.num_vdev_recvd) ==
+				  total_vdevs_started);
 
 		list_splice_tail_init(&stats->vdevs,
 				      &ar->fw_stats.vdevs);
@@ -8204,7 +8206,9 @@ static void ath12k_wmi_fw_stats_process(struct ath12k *ar,
 		/* Mark end until we reached the count of all started VDEVs
 		 * within the PDEV
 		 */
-		is_end = ((++ar->fw_stats.num_bcn_recvd) == ar->num_started_vdevs);
+		if (ar->num_started_vdevs)
+			is_end = ((++ar->fw_stats.num_bcn_recvd) ==
+				  ar->num_started_vdevs);
 
 		list_splice_tail_init(&stats->bcn,
 				      &ar->fw_stats.bcn);