Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel os linux

siox: don't create a thread without starting it

When a siox master device is registered a kthread is created that is
only started when triggered by userspace. So this thread might be in
TASK_UNINTERRUPTIBLE state for long and trigger a warning

[ 241.130465] INFO: task siox-0:626 blocked for more than 120 seconds.

with the respective debug settings enabled. It might be right to put an
unstarted thread to TASK_IDLE (in kernel/kthread.c:kthread()) instead,
but independant of this discussion it is cleaner for
siox_master_register() to start the thread immediately. The effect is
that it enters its own waiting state and then stays in state TASK_IDLE
which doesn't trigger the above warning.

As siox_poll_thread() uses some variables of the device the
initialisation of these is moved before thread creation.

Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Gavin Schenk <g.schenk@eckelmann.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

authored by

Uwe Kleine-König and committed by
Greg Kroah-Hartman
e8905914 7e6f7d24

+5 -5
+5 -5
drivers/siox/siox-core.c
··· 715 715 716 716 dev_set_name(&smaster->dev, "siox-%d", smaster->busno); 717 717 718 + mutex_init(&smaster->lock); 719 + INIT_LIST_HEAD(&smaster->devices); 720 + 718 721 smaster->last_poll = jiffies; 719 - smaster->poll_thread = kthread_create(siox_poll_thread, smaster, 720 - "siox-%d", smaster->busno); 722 + smaster->poll_thread = kthread_run(siox_poll_thread, smaster, 723 + "siox-%d", smaster->busno); 721 724 if (IS_ERR(smaster->poll_thread)) { 722 725 smaster->active = 0; 723 726 return PTR_ERR(smaster->poll_thread); 724 727 } 725 - 726 - mutex_init(&smaster->lock); 727 - INIT_LIST_HEAD(&smaster->devices); 728 728 729 729 ret = device_add(&smaster->dev); 730 730 if (ret)