nfc: Fix hangup of RC-S380* in port100_send_ack()
commit 2497128133f8169b24b928852ba6eae34fc495e5 upstream.
If port100_send_ack() was called twice or more, it has race to hangup.
port100_send_ack() port100_send_ack()
init_completion()
[...]
dev->cmd_cancel = true
/* this removes previous from completion */
init_completion()
[...]
dev->cmd_cancel = true
wait_for_completion()
/* never be waked up */
wait_for_completion()
Like above race, this code is not assuming port100_send_ack() is
called twice or more.
To fix, this checks dev->cmd_cancel to know if prior cancel is
in-flight or not. And never be remove prior task from completion by
using reinit_completion(), so this guarantees to be waked up properly
soon or later.
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
1 file changed