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wifi: mt76: mt7921: refactor regd update to fix recursive mutex deadlock

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Split mt7921_mcu_regd_update() into two functions to prevent recursive
mutex acquisition. Introduce __mt7921_mcu_regd_update() as the internal
implementation that assumes the mutex is already held by the caller,
while mt7921_mcu_regd_update() remains as the external interface that
handles mutex acquisition and release.

This fixes a deadlock issue when mt7921_regd_set_6ghz_power_type() is
called with the device mutex already held. Without this change, calling
mt7921_mcu_regd_update() would attempt to acquire the same mutex again,
causing a recursive lock deadlock.

The __mt7921_mcu_regd_update() function can be safely called when the
caller has already acquired the device mutex, avoiding the deadlock
while maintaining proper synchronization for regulatory domain updates.

Fixes: dc2608cf5224 ("wifi: mt76: mt7921: refactor regulatory notifier flow")
Signed-off-by: Charlie-cy Wu <Charlie-cy.Wu@mediatek.com>
Tested-by: Mikhail Gavrilov <mikhail.v.gavrilov@gmail.com>
Tested-by: Devin Wittmayer <lucid_duck@justthetip.ca>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Charlie-cy Wu 2026-06-29 16:35:43 +08:00 committed by Linus Torvalds
parent d5b95e612c
commit d6e7d57ed9
3 changed files with 22 additions and 12 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
drivers/net/wireless/mediatek/mt76/mt7921/main.c
View File

@ -802,7 +802,7 @@ mt7921_regd_set_6ghz_power_type(struct ieee80211_vif *vif, bool is_add)
out:
if (vif->bss_conf.chanreq.oper.chan->band == NL80211_BAND_6GHZ)
mt7921_mcu_regd_update(dev, dev->mt76.alpha2, dev->country_ie_env);
__mt7921_mcu_regd_update(dev, dev->mt76.alpha2, dev->country_ie_env);
}
int mt7921_mac_sta_add(struct mt76_dev *mdev, struct ieee80211_vif *vif,

30
drivers/net/wireless/mediatek/mt76/mt7921/regd.c
View File

@ -71,36 +71,44 @@ mt7921_regd_channel_update(struct wiphy *wiphy, struct mt792x_dev *dev)
}
}
int mt7921_mcu_regd_update(struct mt792x_dev *dev, u8 *alpha2,
enum environment_cap country_ie_env)
/* Internal version that assumes mutex is already held by caller */
int __mt7921_mcu_regd_update(struct mt792x_dev *dev, u8 *alpha2,
enum environment_cap country_ie_env)
{
struct mt76_dev *mdev = &dev->mt76;
struct ieee80211_hw *hw = mdev->hw;
struct wiphy *wiphy = hw->wiphy;
int ret = 0;
dev->regd_in_progress = true;
mt792x_mutex_acquire(dev);
if (!dev->regd_change)
goto err;
return 0;
ret = mt7921_mcu_set_clc(dev, alpha2, country_ie_env);
if (ret < 0)
goto err;
return ret;
mt7921_regd_channel_update(wiphy, dev);
ret = mt76_connac_mcu_set_channel_domain(hw->priv);
if (ret < 0)
goto err;
return ret;
ret = mt7921_set_tx_sar_pwr(hw, NULL);
if (ret < 0)
goto err;
err:
return ret;
}
int mt7921_mcu_regd_update(struct mt792x_dev *dev, u8 *alpha2,
enum environment_cap country_ie_env)
{
int ret = 0;
dev->regd_in_progress = true;
mt792x_mutex_acquire(dev);
ret = __mt7921_mcu_regd_update(dev, alpha2, country_ie_env);
mt792x_mutex_release(dev);
dev->regd_change = false;
dev->regd_in_progress = false;
wake_up(&dev->wait);

2
drivers/net/wireless/mediatek/mt76/mt7921/regd.h
View File

@ -10,6 +10,8 @@ struct regulatory_request;
int mt7921_mcu_regd_update(struct mt792x_dev *dev, u8 *alpha2,
enum environment_cap country_ie_env);
int __mt7921_mcu_regd_update(struct mt792x_dev *dev, u8 *alpha2,
enum environment_cap country_ie_env);
void mt7921_regd_notifier(struct wiphy *wiphy,
struct regulatory_request *request);
bool mt7921_regd_clc_supported(struct mt792x_dev *dev);