wifi: rtw89: Un-embed dummy device

Embedding net_device into structures prohibits the usage of flexible
arrays in the net_device structure. For more details, see the discussion
at [1].

Un-embed the net_device from the private struct by converting it
into a pointer. Then use the leverage the new alloc_netdev_dummy()
helper to allocate and initialize dummy devices.

[1] https://lore.kernel.org/all/20240229225910.79e224cf@kernel.org/

Tested with RTL8852BE, RTL8852C and RTL8922AE.
Signed-off-by: Breno Leitao <leitao@debian.org>
Acked-by: Ping-Ke Shih <pkshih@realtek.com>
Tested-by: Ping-Ke Shih <pkshih@realtek.com>
Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Link: https://msgid.link/20240424182351.3936556-1-leitao@debian.org

drivers/net/wireless/realtek/rtw89/core.c

@@ -2492,11 +2492,15 @@ void rtw89_core_napi_stop(struct rtw89_dev *rtwdev)
 }
 EXPORT_SYMBOL(rtw89_core_napi_stop);
 
-void rtw89_core_napi_init(struct rtw89_dev *rtwdev)
+int rtw89_core_napi_init(struct rtw89_dev *rtwdev)
 {
-	init_dummy_netdev(&rtwdev->netdev);
-	netif_napi_add(&rtwdev->netdev, &rtwdev->napi,
+	rtwdev->netdev = alloc_netdev_dummy(0);
+	if (!rtwdev->netdev)
+		return -ENOMEM;
+
+	netif_napi_add(rtwdev->netdev, &rtwdev->napi,
 		       rtwdev->hci.ops->napi_poll);
+	return 0;
 }
 EXPORT_SYMBOL(rtw89_core_napi_init);
 
@@ -2504,6 +2508,7 @@ void rtw89_core_napi_deinit(struct rtw89_dev *rtwdev)
 {
 	rtw89_core_napi_stop(rtwdev);
 	netif_napi_del(&rtwdev->napi);
+	free_netdev(rtwdev->netdev);
 }
 EXPORT_SYMBOL(rtw89_core_napi_deinit);
 

drivers/net/wireless/realtek/rtw89/core.h

@@ -5469,7 +5469,7 @@ struct rtw89_dev {
 	struct rtw89_wow_param wow;
 
 	/* napi structure */
-	struct net_device netdev;
+	struct net_device *netdev;
 	struct napi_struct napi;
 	int napi_budget_countdown;
 
@@ -6441,7 +6441,7 @@ void rtw89_core_query_rxdesc_v2(struct rtw89_dev *rtwdev,
 				u8 *data, u32 data_offset);
 void rtw89_core_napi_start(struct rtw89_dev *rtwdev);
 void rtw89_core_napi_stop(struct rtw89_dev *rtwdev);
-void rtw89_core_napi_init(struct rtw89_dev *rtwdev);
+int rtw89_core_napi_init(struct rtw89_dev *rtwdev);
 void rtw89_core_napi_deinit(struct rtw89_dev *rtwdev);
 int rtw89_core_sta_add(struct rtw89_dev *rtwdev,
 		       struct ieee80211_vif *vif,

drivers/net/wireless/realtek/rtw89/pci.c

@@ -4293,7 +4293,11 @@ int rtw89_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 	rtw89_pci_link_cfg(rtwdev);
 	rtw89_pci_l1ss_cfg(rtwdev);
 
-	rtw89_core_napi_init(rtwdev);
+	ret = rtw89_core_napi_init(rtwdev);
+	if (ret) {
+		rtw89_err(rtwdev, "failed to init napi\n");
+		goto err_clear_resource;
+	}
 
 	ret = rtw89_pci_request_irq(rtwdev, pdev);
 	if (ret) {