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tty/hvc/hvc_console: Fix wakeup of HVC thread on hvc_kick()

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Some backends call hvc_kick() to wakeup the HVC thread from its
slumber upon incoming characters. This however doesn't work
properly because it uses msleep_interruptible() which is mostly
immune to wake_up_process(). It will basically go back to sleep
until the timeout is expired (only signals can really wake it).

Replace it with a simple shedule_timeout_interruptible() instead,
which may wakeup earlier every now and then but we really don't
care in this case.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Benjamin Herrenschmidt 2014-05-23 19:41:06 +10:00 committed by Greg Kroah-Hartman
parent 8e25f8ce0e
commit 15a2743193
1 changed files with 8 additions and 1 deletions
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9
drivers/tty/hvc/hvc_console.c
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@ -760,10 +760,17 @@ static int khvcd(void *unused)
if (poll_mask == 0)
schedule();
else {
unsigned long j_timeout;
if (timeout < MAX_TIMEOUT)
timeout += (timeout >> 6) + 1;
msleep_interruptible(timeout);
/*
* We don't use msleep_interruptible otherwise
* "kick" will fail to wake us up
*/
j_timeout = msecs_to_jiffies(timeout) + 1;
schedule_timeout_interruptible(j_timeout);
}
}
__set_current_state(TASK_RUNNING);