Thread (5 messages) 5 messages, 4 authors, 2015-03-11

confusing code....whats the point of this construct ?

From: bjorn@mork.no (Bjørn Mork)
Date: 2015-03-11 15:09:25

Possibly related (same subject, not in this thread)

Valdis.Kletnieks at vt.edu writes:
On Wed, 11 Mar 2015 15:17:44 +0100, Nicholas Mc Guire said:
quoted
So the wait_event_timeout condition here ends up being (empty || skip)
but what is the point of puting this code into the parameter list of
wait_event_timeout() ?

Would it not be equivalent to:

	bool empty;
	...

	spin_lock_bh(&ar->htt.tx_lock);
	empty = (ar->htt.num_pending_tx == 0);
	spin_unlock_bh(&ar->htt.tx_lock);

	skip = (ar->state == ATH10K_STATE_WEDGED) ||
		test_bit(ATH10K_FLAG_CRASH_FLUSH,
		&ar->dev_flags);

	ret = wait_event_timeout(ar->htt.empty_tx_wq, (empty || skip),
				 ATH10K_FLUSH_TIMEOUT_HZ);

What am I missing here ?
Umm... a Signed-off-by: and formatting it as an actual patch? :)

Seriously - you're right, it's ugly code that needs fixing...
Huh?

The condition needs to be re-evaluated every time the process wakes up.
Evaluating it once and then reusing that result is not the same.
Something elseis supposed to modify ar->htt.num_pending_tx, ar->state or
ar->dev_flags while we are waiting.



Bj?rn
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