On 1/23/2023 12:50 AM, Manivannan Sadhasivam wrote:
state_lock, the spinlock type is meant to protect race against concurrent MHI state transitions. In mhi_ep_set_m0_state(), while the state_lock is being held, the channels are resumed in mhi_ep_resume_channels() if the previous state was M3. This causes sleeping in atomic bug, since mhi_ep_resume_channels() use mutex internally.
Since the state_lock is supposed to be held throughout the state change, it is not ideal to drop the lock before calling mhi_ep_resume_channels(). So to fix this issue, let's change the type of state_lock to mutex. This would also allow holding the lock throughout all state transitions thereby avoiding any potential race.
Cc: stable@vger.kernel.org # 5.19 Fixes: e4b7b5f0f30a ("bus: mhi: ep: Add support for suspending and resuming channels") Reported-by: Dan Carpenter error27@gmail.com Signed-off-by: Manivannan Sadhasivam manivannan.sadhasivam@linaro.org
Looks sane. Reviewed-by: Jeffrey Hugo quic_jhugo@quicinc.com