wifi: ath12k: fix the stack frame size warning in ath12k_mac_op_hw_scan

Fix the following W=1 kernel build warning:

drivers/net/wireless/ath/ath12k/mac.c: In function ‘ath12k_mac_op_hw_scan’:
drivers/net/wireless/ath/ath12k/mac.c:3806:1: warning: the frame size of 1040 bytes is larger than 1024 bytes [-Wframe-larger-than=]

Tested-on: WCN7850 hw2.0 PCI WLAN.HMT.1.0.c5-00481-QCAHMTSWPL_V1.0_V2.0_SILICONZ-3

Signed-off-by: Miaoqing Pan <quic_miaoqing@quicinc.com>
Acked-by: Jeff Johnson <quic_jjohnson@quicinc.com>
Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>
Link: https://patch.msgid.link/20240809015841.2671448-1-quic_miaoqing@quicinc.com

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

@@ -3663,7 +3663,7 @@ static int ath12k_mac_op_hw_scan(struct ieee80211_hw *hw,
 	struct ath12k *ar, *prev_ar;
 	struct ath12k_vif *arvif = ath12k_vif_to_arvif(vif);
 	struct cfg80211_scan_request *req = &hw_req->req;
-	struct ath12k_wmi_scan_req_arg arg = {};
+	struct ath12k_wmi_scan_req_arg *arg = NULL;
 	int ret;
 	int i;
 	bool create = true;
@@ -3745,42 +3745,47 @@ static int ath12k_mac_op_hw_scan(struct ieee80211_hw *hw,
 	if (ret)
 		goto exit;
 
-	ath12k_wmi_start_scan_init(ar, &arg);
-	arg.vdev_id = arvif->vdev_id;
-	arg.scan_id = ATH12K_SCAN_ID;
+	arg = kzalloc(sizeof(*arg), GFP_KERNEL);
+	if (!arg) {
+		ret = -ENOMEM;
+		goto exit;
+	}
+
+	ath12k_wmi_start_scan_init(ar, arg);
+	arg->vdev_id = arvif->vdev_id;
+	arg->scan_id = ATH12K_SCAN_ID;
 
 	if (req->ie_len) {
-		arg.extraie.ptr = kmemdup(req->ie, req->ie_len, GFP_KERNEL);
-		if (!arg.extraie.ptr) {
+		arg->extraie.ptr = kmemdup(req->ie, req->ie_len, GFP_KERNEL);
+		if (!arg->extraie.ptr) {
 			ret = -ENOMEM;
 			goto exit;
 		}
-		arg.extraie.len = req->ie_len;
+		arg->extraie.len = req->ie_len;
 	}
 
 	if (req->n_ssids) {
-		arg.num_ssids = req->n_ssids;
-		for (i = 0; i < arg.num_ssids; i++)
-			arg.ssid[i] = req->ssids[i];
+		arg->num_ssids = req->n_ssids;
+		for (i = 0; i < arg->num_ssids; i++)
+			arg->ssid[i] = req->ssids[i];
 	} else {
-		arg.scan_f_passive = 1;
+		arg->scan_f_passive = 1;
 	}
 
 	if (req->n_channels) {
-		arg.num_chan = req->n_channels;
-		arg.chan_list = kcalloc(arg.num_chan, sizeof(*arg.chan_list),
-					GFP_KERNEL);
-
-		if (!arg.chan_list) {
+		arg->num_chan = req->n_channels;
+		arg->chan_list = kcalloc(arg->num_chan, sizeof(*arg->chan_list),
+					 GFP_KERNEL);
+		if (!arg->chan_list) {
 			ret = -ENOMEM;
 			goto exit;
 		}
 
-		for (i = 0; i < arg.num_chan; i++)
-			arg.chan_list[i] = req->channels[i]->center_freq;
+		for (i = 0; i < arg->num_chan; i++)
+			arg->chan_list[i] = req->channels[i]->center_freq;
 	}
 
-	ret = ath12k_start_scan(ar, &arg);
+	ret = ath12k_start_scan(ar, arg);
 	if (ret) {
 		ath12k_warn(ar->ab, "failed to start hw scan: %d\n", ret);
 		spin_lock_bh(&ar->data_lock);
@@ -3790,14 +3795,15 @@ static int ath12k_mac_op_hw_scan(struct ieee80211_hw *hw,
 
 	/* Add a margin to account for event/command processing */
 	ieee80211_queue_delayed_work(ath12k_ar_to_hw(ar), &ar->scan.timeout,
-				     msecs_to_jiffies(arg.max_scan_time +
+				     msecs_to_jiffies(arg->max_scan_time +
 						      ATH12K_MAC_SCAN_TIMEOUT_MSECS));
 
 exit:
-	kfree(arg.chan_list);
-
-	if (req->ie_len)
-		kfree(arg.extraie.ptr);
+	if (arg) {
+		kfree(arg->chan_list);
+		kfree(arg->extraie.ptr);
+		kfree(arg);
+	}
 
 	mutex_unlock(&ar->conf_mutex);