linux-kernel - [PATCH net-next 2/6] net: ipa: reorder netdev pointer assignments

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Date:   Wed,  4 Aug 2021 10:36:22 -0500
From:   Alex Elder <elder@...aro.org>
To:     davem@...emloft.net, kuba@...nel.org
Cc:     bjorn.andersson@...aro.org, evgreen@...omium.org,
        cpratapa@...eaurora.org, subashab@...eaurora.org, elder@...nel.org,
        netdev@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [PATCH net-next 2/6] net: ipa: reorder netdev pointer assignments

Assign the ipa->modem_netdev and endpoint->netdev pointers *before*
registering the network device.  As soon as the device is
registered it can be opened, and by that time we'll want those
pointers valid.

Similarly, don't make those pointers NULL until *after* the modem
network device is unregistered in ipa_modem_stop().

Signed-off-by: Alex Elder <elder@...aro.org>
---
 drivers/net/ipa/ipa_modem.c | 18 ++++++++++--------
 1 file changed, 10 insertions(+), 8 deletions(-)

diff --git a/drivers/net/ipa/ipa_modem.c b/drivers/net/ipa/ipa_modem.c
index 663a610979e70..ad4019e8016ec 100644
--- a/drivers/net/ipa/ipa_modem.c
+++ b/drivers/net/ipa/ipa_modem.c
@@ -231,13 +231,15 @@ int ipa_modem_start(struct ipa *ipa)
 	SET_NETDEV_DEV(netdev, &ipa->pdev->dev);
 	priv = netdev_priv(netdev);
 	priv->ipa = ipa;
+	ipa->name_map[IPA_ENDPOINT_AP_MODEM_TX]->netdev = netdev;
+	ipa->name_map[IPA_ENDPOINT_AP_MODEM_RX]->netdev = netdev;
+	ipa->modem_netdev = netdev;
 
 	ret = register_netdev(netdev);
-	if (!ret) {
-		ipa->modem_netdev = netdev;
-		ipa->name_map[IPA_ENDPOINT_AP_MODEM_TX]->netdev = netdev;
-		ipa->name_map[IPA_ENDPOINT_AP_MODEM_RX]->netdev = netdev;
-	} else {
+	if (ret) {
+		ipa->modem_netdev = NULL;
+		ipa->name_map[IPA_ENDPOINT_AP_MODEM_RX]->netdev = NULL;
+		ipa->name_map[IPA_ENDPOINT_AP_MODEM_TX]->netdev = NULL;
 		free_netdev(netdev);
 	}
 
@@ -276,10 +278,10 @@ int ipa_modem_stop(struct ipa *ipa)
 		/* If it was opened, stop it first */
 		if (netdev->flags & IFF_UP)
 			(void)ipa_stop(netdev);
-		ipa->name_map[IPA_ENDPOINT_AP_MODEM_RX]->netdev = NULL;
-		ipa->name_map[IPA_ENDPOINT_AP_MODEM_TX]->netdev = NULL;
-		ipa->modem_netdev = NULL;
 		unregister_netdev(netdev);
+		ipa->modem_netdev = NULL;
+		ipa->name_map[IPA_ENDPOINT_AP_MODEM_RX]->netdev = NULL;
+		ipa->name_map[IPA_ENDPOINT_AP_MODEM_TX]->netdev = NULL;
 		free_netdev(netdev);
 	}
 
-- 
2.27.0