2021-03-05 08:47:52

by Ryder Lee

[permalink] [raw]
Subject: [PATCH] mt76: mt7915: fix possible deadlock while mt7915_register_ext_phy()

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 mt7915_register_ext_phy() outside the init_work().

Signed-off-by: Evelyn Tsai <[email protected]>
Signed-off-by: Ryder Lee <[email protected]>
---
drivers/net/wireless/mediatek/mt76/mt7915/init.c | 7 ++++---
drivers/net/wireless/mediatek/mt76/mt7915/main.c | 4 ++++
2 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/drivers/net/wireless/mediatek/mt76/mt7915/init.c b/drivers/net/wireless/mediatek/mt76/mt7915/init.c
index 165be6abcc96..2ffadd22c259 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7915/init.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7915/init.c
@@ -181,8 +181,6 @@ static void mt7915_mac_init(struct mt7915_dev *dev)
MT_WTBL_UPDATE_ADM_COUNT_CLEAR);
for (i = 0; i < 2; i++)
mt7915_mac_init_band(dev, i);
-
- mt7915_mcu_set_rts_thresh(&dev->phy, 0x92b);
}

static int mt7915_txbf_init(struct mt7915_dev *dev)
@@ -295,7 +293,6 @@ static void mt7915_init_work(struct work_struct *work)
mt7915_mac_init(dev);
mt7915_init_txpower(dev);
mt7915_txbf_init(dev);
- mt7915_register_ext_phy(dev);
}

static int mt7915_init_hardware(struct mt7915_dev *dev)
@@ -677,6 +674,10 @@ int mt7915_register_device(struct mt7915_dev *dev)

ieee80211_queue_work(mt76_hw(dev), &dev->init_work);

+ ret = mt7915_register_ext_phy(dev);
+ if (ret)
+ return ret;
+
return mt7915_init_debugfs(dev);
}

diff --git a/drivers/net/wireless/mediatek/mt76/mt7915/main.c b/drivers/net/wireless/mediatek/mt76/mt7915/main.c
index 255f87aa1830..cde8c1ce3ae0 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7915/main.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7915/main.c
@@ -65,6 +65,10 @@ static int mt7915_start(struct ieee80211_hw *hw)
mt7915_mac_enable_nf(dev, 1);
}

+ ret = mt7915_mcu_set_rts_thresh(phy, 0x92b);
+ if (ret)
+ goto out;
+
ret = mt7915_mcu_set_sku_en(phy, true);
if (ret)
goto out;
--
2.18.0