From: Bhaumik Bhatt <bbhatt@codeaurora.org>
Date: Thu, 15 Oct 2020 18:47:51 +0000 (-0700)
Subject: bus: mhi: core: Remove double locking from mhi_driver_remove()
X-Git-Tag: v5.11-rc1~164^2~48^2~27
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=9b627c25e70816a5e1dca940444b5029065b4d60;p=thirdparty%2Fkernel%2Flinux.git

bus: mhi: core: Remove double locking from mhi_driver_remove()

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>
---

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;
 }