arch: xtensa: platforms: Fix deadlock in rs_close()
There is a deadlock in rs_close(), which is shown below: (Thread 1) | (Thread 2) | rs_open() rs_close() | mod_timer() spin_lock_bh() //(1) | (wait a time) ... | rs_poll() del_timer_sync() | spin_lock() //(2) (wait timer to stop) | ... We hold timer_lock in position (1) of thread 1 and use del_timer_sync() to wait timer to stop, but timer handler also need timer_lock in position (2) of thread 2. As a result, rs_close() will block forever. This patch deletes the redundant timer_lock in order to prevent the deadlock. Because there is no race condition between rs_close, rs_open and rs_poll. Signed-off-by:Duoming Zhou <duoming@zju.edu.cn> Message-Id: <20220407154430.22387-1-duoming@zju.edu.cn> Signed-off-by:
Max Filippov <jcmvbkbc@gmail.com>
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