This is a note to let you know that I've just added the patch titled mt76: mt7921: fix dma hang in rmmod to the 5.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: mt76-mt7921-fix-dma-hang-in-rmmod.patch and it can be found in the queue-5.14 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 89320081a7a2b9fea6818f5fd5b337ccf0096395 Author: Deren Wu <deren.wu@xxxxxxxxxxxx> Date: Tue Jul 27 17:47:09 2021 +0800 mt76: mt7921: fix dma hang in rmmod [ Upstream commit a23f80aa9c5e6ad4ec8df88037b7ffd4162b1ec4 ] The dma would be broken after rmmod flow. There are two different cases causing this issue. 1. dma access without privilege. 2. hw access sequence borken by another context. This patch handle both cases to avoid hw crash. Fixes: 2b9ea5a8cf1bd ("mt76: mt7921: add mt7921_dma_cleanup in mt7921_unregister_device") Signed-off-by: Deren Wu <deren.wu@xxxxxxxxxxxx> Signed-off-by: Felix Fietkau <nbd@xxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/net/wireless/mediatek/mt76/mt7921/init.c b/drivers/net/wireless/mediatek/mt76/mt7921/init.c index 52d40385fab6c..78a00028137bd 100644 --- a/drivers/net/wireless/mediatek/mt76/mt7921/init.c +++ b/drivers/net/wireless/mediatek/mt76/mt7921/init.c @@ -251,8 +251,17 @@ int mt7921_register_device(struct mt7921_dev *dev) void mt7921_unregister_device(struct mt7921_dev *dev) { + int i; + struct mt76_connac_pm *pm = &dev->pm; + mt76_unregister_device(&dev->mt76); + mt76_for_each_q_rx(&dev->mt76, i) + napi_disable(&dev->mt76.napi[i]); + cancel_delayed_work_sync(&pm->ps_work); + cancel_work_sync(&pm->wake_work); + mt7921_tx_token_put(dev); + mt7921_mcu_drv_pmctrl(dev); mt7921_dma_cleanup(dev); mt7921_mcu_exit(dev);