Hi!
There is a bug in drivers/iio/light/opt3001.ko. Regard such case:
Thread 1 Thread 2
-> opt3001_read_raw
-> mutex_lock(&opt->lock)
-> opt3001_get_lux()
..
->i2c_smbus_write_word_swapped()
Now an interrupt comes
-> opt3001_irq
-> mutex_lock(&opt->lock)
This is a deadlock, as the flag ok_to_ignore_lock has not been set yet.
Regard another case:
Thread 1 Thread 2
-> opt3001_read_raw
-> mutex_lock(&opt->lock)
-> opt3001_get_lux()
..
-> i2c_smbus_write_word_swapped()
opt->ok_to_ignore_lock = true;
Now an interrupt comes
-> opt3001_irq
..
opt->result_ready = true
wake_up()
opt->result_ready = false;
wait_event_timeout()
In this case the first thread misses the result and waits until timeout
expires.
--
Pavel Andrianov
Linux Verification Center, ISPRAS
web: http://linuxtesting.org
e-mail: andrianov@xxxxxxxxx
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