4.18-stable review patch. If anyone has any objections, please let me know.
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From: Uwe Kleine-König u.kleine-koenig@pengutronix.de
[ Upstream commit e890591413819eeb604207ad3261ba617b2ec0bb ]
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 Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/siox/siox-core.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-)
--- a/drivers/siox/siox-core.c +++ b/drivers/siox/siox-core.c @@ -715,17 +715,17 @@ int siox_master_register(struct siox_mas
dev_set_name(&smaster->dev, "siox-%d", smaster->busno);
+ mutex_init(&smaster->lock); + INIT_LIST_HEAD(&smaster->devices); + smaster->last_poll = jiffies; - smaster->poll_thread = kthread_create(siox_poll_thread, smaster, - "siox-%d", smaster->busno); + smaster->poll_thread = kthread_run(siox_poll_thread, smaster, + "siox-%d", smaster->busno); if (IS_ERR(smaster->poll_thread)) { smaster->active = 0; return PTR_ERR(smaster->poll_thread); }
- mutex_init(&smaster->lock); - INIT_LIST_HEAD(&smaster->devices); - ret = device_add(&smaster->dev); if (ret) kthread_stop(smaster->poll_thread);