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net/irda: Use barrier to set task state

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Without a memory and compiler barrier, the task state change
can migrate relative to the condition testing in a blocking loop.
However, the task state change must be visible across all cpus
prior to testing those conditions. Failing to do this can result
in the familiar 'lost wakeup' and this task will hang until killed.

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Peter Hurley 2013-03-05 06:09:06 +00:00 committed by David S. Miller
parent 2f7c069b96
commit 0b176ce3a7
1 changed files with 1 additions and 1 deletions
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2
net/irda/ircomm/ircomm_tty.c
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@ -324,7 +324,7 @@ static int ircomm_tty_block_til_ready(struct ircomm_tty_cb *self,
if (tty->termios.c_cflag & CBAUD)
tty_port_raise_dtr_rts(port);
current->state = TASK_INTERRUPTIBLE;
set_current_state(TASK_INTERRUPTIBLE);
if (tty_hung_up_p(filp) ||
!test_bit(ASYNCB_INITIALIZED, &port->flags)) {