[PATCH 5.16 0669/1039] mt76: mt7615: fix possible deadlock while mt7615_register_ext_phy()

From: Greg Kroah-Hartman
Date: Mon Jan 24 2022 - 17:16:06 EST


From: Peter Chiu <chui-hao.chiu@xxxxxxxxxxxx>

[ 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@xxxxxxxxxxxx>
Signed-off-by: Felix Fietkau <nbd@xxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
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