From: Lorenzo Bianconi lorenzo@kernel.org
[ Upstream commit 591cdccebdd4d02eb46d400dea911136400cc567 ]
Fix a possible race in mt7921_pm_power_save_work() if rx/tx napi schedules ps_work and we are currently accessing device register on a different cpu.
Fixes: 1d8efc741df8 ("mt76: mt7921: introduce Runtime PM support") Signed-off-by: Lorenzo Bianconi lorenzo@kernel.org Signed-off-by: Felix Fietkau nbd@nbd.name Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/wireless/mediatek/mt76/mt7921/mac.c | 8 ++++++++ 1 file changed, 8 insertions(+)
diff --git a/drivers/net/wireless/mediatek/mt76/mt7921/mac.c b/drivers/net/wireless/mediatek/mt76/mt7921/mac.c index ec10f95a4649..3e83a0c33143 100644 --- a/drivers/net/wireless/mediatek/mt76/mt7921/mac.c +++ b/drivers/net/wireless/mediatek/mt76/mt7921/mac.c @@ -1551,6 +1551,14 @@ void mt7921_pm_power_save_work(struct work_struct *work) test_bit(MT76_HW_SCHED_SCANNING, &mphy->state)) goto out;
+ if (mutex_is_locked(&dev->mt76.mutex)) + /* if mt76 mutex is held we should not put the device + * to sleep since we are currently accessing device + * register map. We need to wait for the next power_save + * trigger. + */ + goto out; + if (time_is_after_jiffies(dev->pm.last_activity + delta)) { delta = dev->pm.last_activity + delta - jiffies; goto out;