• Manivannan Sadhasivam's avatar
    bus: mhi: ep: Change state_lock to mutex · 1ddc7618
    Manivannan Sadhasivam authored
    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: e4b7b5f0 ("bus: mhi: ep: Add support for suspending and resuming channels")
    Reported-by: default avatarDan Carpenter <error27@gmail.com>
    Reviewed-by: default avatarJeffrey Hugo <quic_jhugo@quicinc.com>
    Signed-off-by: default avatarManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
    1ddc7618
sm.c 3.88 KB