[PATCH wireless-next] wifi: rtw88: Un-embed dummy device

[Breno Leitao <leitao@debian.org>]

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/

Signed-off-by: Breno Leitao <leitao@debian.org>
---
 drivers/net/wireless/realtek/rtw88/pci.c | 17 +++++++++++++----
 drivers/net/wireless/realtek/rtw88/pci.h |  2 +-
 2 files changed, 14 insertions(+), 5 deletions(-)

PS: This is compile-tested only due to lack of hardware to do better
testing.

diff --git a/drivers/net/wireless/realtek/rtw88/pci.c b/drivers/net/wireless/realtek/rtw88/pci.c
index 9986a4cb37eb..4ff4f875cefb 100644
--- a/drivers/net/wireless/realtek/rtw88/pci.c
+++ b/drivers/net/wireless/realtek/rtw88/pci.c
@@ -1681,12 +1681,16 @@ static int rtw_pci_napi_poll(struct napi_struct *napi, int budget)
 	return work_done;
 }
 
-static void rtw_pci_napi_init(struct rtw_dev *rtwdev)
+static int rtw_pci_napi_init(struct rtw_dev *rtwdev)
 {
 	struct rtw_pci *rtwpci = (struct rtw_pci *)rtwdev->priv;
 
-	init_dummy_netdev(&rtwpci->netdev);
-	netif_napi_add(&rtwpci->netdev, &rtwpci->napi, rtw_pci_napi_poll);
+	rtwpci->netdev = alloc_netdev_dummy(0);
+	if (!rtwpci->netdev)
+		return -ENOMEM;
+
+	netif_napi_add(rtwpci->netdev, &rtwpci->napi, rtw_pci_napi_poll);
+	return 0;
 }
 
 static void rtw_pci_napi_deinit(struct rtw_dev *rtwdev)
@@ -1695,6 +1699,7 @@ static void rtw_pci_napi_deinit(struct rtw_dev *rtwdev)
 
 	rtw_pci_napi_stop(rtwdev);
 	netif_napi_del(&rtwpci->napi);
+	free_netdev(rtwpci->netdev);
 }
 
 int rtw_pci_probe(struct pci_dev *pdev,
@@ -1744,7 +1749,11 @@ int rtw_pci_probe(struct pci_dev *pdev,
 		goto err_pci_declaim;
 	}
 
-	rtw_pci_napi_init(rtwdev);
+	ret = rtw_pci_napi_init(rtwdev);
+	if (ret) {
+		rtw_err(rtwdev, "failed to setup NAPI\n");
+		goto err_pci_declaim;
+	}
 
 	ret = rtw_chip_info_setup(rtwdev);
 	if (ret) {
diff --git a/drivers/net/wireless/realtek/rtw88/pci.h b/drivers/net/wireless/realtek/rtw88/pci.h
index 0c37efd8c66f..13988db1cb4c 100644
--- a/drivers/net/wireless/realtek/rtw88/pci.h
+++ b/drivers/net/wireless/realtek/rtw88/pci.h
@@ -215,7 +215,7 @@ struct rtw_pci {
 	bool running;
 
 	/* napi structure */
-	struct net_device netdev;
+	struct net_device *netdev;
 	struct napi_struct napi;
 
 	u16 rx_tag;
-- 
2.43.0