wifi: ath11k: 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
ath11k_debugfs_fw_stats_process() we wait 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)

finally the requestor would be blocked until wait 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
wait directly; if not, follow the old way.

Tested-on: WCN6855 hw2.0 PCI WLAN.HSP.1.1-03125-QCAHSPSWPL_V1_V2_SILICONZ_LITE-3.6510.37

Fixes: d5c6515 ("ath11k: driver for Qualcomm IEEE 802.11ax devices")
Signed-off-by: Baochen Qiang <[email protected]>
Reviewed-by: Vasanthakumar Thiagarajan <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jeff Johnson <[email protected]>

Author: Baochen Qiang

drivers/net/wireless/ath/ath11k/debugfs.c

@@ -107,7 +107,7 @@ void ath11k_debugfs_fw_stats_process(struct ath11k *ar, struct ath11k_fw_stats *
 {
 	struct ath11k_base *ab = ar->ab;
 	struct ath11k_pdev *pdev;
-	bool is_end;
+	bool is_end = true;
 	size_t total_vdevs_started = 0;
 	int i;
 
@@ -132,7 +132,9 @@ void ath11k_debugfs_fw_stats_process(struct ath11k *ar, struct ath11k_fw_stats *
 				total_vdevs_started += ar->num_started_vdevs;
 		}
 
-		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);
@@ -151,7 +153,9 @@ void ath11k_debugfs_fw_stats_process(struct ath11k *ar, struct ath11k_fw_stats *
 		/* 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);