[PATCH 5.10 150/717] bus: mhi: core: Remove double locking from mhi_driver_remove()

Greg Kroah-Hartman
2020-12-28T15:09:18Z

From: Bhaumik Bhatt <bbhatt@codeaurora.org>

[ Upstream commit 9b627c25e70816a5e1dca940444b5029065b4d60 ]

There is double acquisition of the pm_lock from mhi_driver_remove()
function. Remove the read_lock_bh/read_unlock_bh calls for pm_lock
taken during a call to mhi_device_put() as the lock is acquired
within the function already. This will help avoid a potential
kernel panic.

Fixes: 189ff97cca53 ("bus: mhi: core: Add support for data transfer")
Reported-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: Bhaumik Bhatt <bbhatt@codeaurora.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/bus/mhi/core/init.c | 2 --
1 file changed, 2 deletions(-)

diff --git a/drivers/bus/mhi/core/init.c b/drivers/bus/mhi/core/init.c
index 0ffdebde82657..0a09f8215057d 100644
--- a/drivers/bus/mhi/core/init.c
+++ b/drivers/bus/mhi/core/init.c
@@ -1276,10 +1276,8 @@ static int mhi_driver_remove(struct device *dev)
mutex_unlock(&mhi_chan->mutex);
}

- read_lock_bh(&mhi_cntrl->pm_lock);
while (mhi_dev->dev_wake)
mhi_device_put(mhi_dev);
- read_unlock_bh(&mhi_cntrl->pm_lock);

return 0;
}
--
2.27.0