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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Peter Chiu <chui-hao.chiu@mediatek.com>,
        Felix Fietkau <nbd@nbd.name>, Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.15 567/846] mt76: mt7615: fix possible deadlock while mt7615_register_ext_phy()
Date:   Mon, 24 Jan 2022 19:41:24 +0100
Message-Id: <20220124184120.586707680@linuxfoundation.org>
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From: Peter Chiu <chui-hao.chiu@mediatek.com>

[ Upstream commit 8c55516de3f9b76b9d9444e7890682ec2efc809f ]

ieee80211_register_hw() is called with rtnl_lock held, and this could be
caused lockdep from a work item that's on a workqueue that is flushed
with the rtnl held.

Move mt7615_register_ext_phy() outside the init_work().

Signed-off-by: Peter Chiu <chui-hao.chiu@mediatek.com>
Signed-off-by: Felix Fietkau <nbd@nbd.name>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/net/wireless/mediatek/mt76/mt7615/pci_init.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/net/wireless/mediatek/mt76/mt7615/pci_init.c b/drivers/net/wireless/mediatek/mt76/mt7615/pci_init.c
index a2465b49ecd0c..87b4aa52ee0f9 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7615/pci_init.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7615/pci_init.c
@@ -28,8 +28,6 @@ static void mt7615_pci_init_work(struct work_struct *work)
 		return;
 
 	mt7615_init_work(dev);
-	if (dev->dbdc_support)
-		mt7615_register_ext_phy(dev);
 }
 
 static int mt7615_init_hardware(struct mt7615_dev *dev)
@@ -160,6 +158,12 @@ int mt7615_register_device(struct mt7615_dev *dev)
 	mt7615_init_txpower(dev, &dev->mphy.sband_2g.sband);
 	mt7615_init_txpower(dev, &dev->mphy.sband_5g.sband);
 
+	if (dev->dbdc_support) {
+		ret = mt7615_register_ext_phy(dev);
+		if (ret)
+			return ret;
+	}
+
 	return mt7615_init_debugfs(dev);
 }
 
-- 
2.34.1