From mboxrd@z Thu Jan  1 00:00:00 1970
From: victorascroft@gmail.com (Victor Ascroft)
Date: Tue, 13 Jan 2015 19:21:40 +0530
Subject: Query on workqueue
Message-ID: <54B522EC.6080601@gmail.com>
To: kernelnewbies@lists.kernelnewbies.org
List-Id: kernelnewbies.lists.kernelnewbies.org

Hello,

Is it ok to use wait_for_completion in a workqueue? 

static void my_work(struct work_struct *work)
{

	while (true)
	{
		wait_for_completion(completion);
		
		// Do something here

		reinit_completion(completion);
		enable_irq(irq);
	}
}

static irqreturn_t my_irq_handler(int irq, void *dev)
{
	disable_irq(irq);

	complete(completion);

	return IRQ_HANDLED;
}

Something like the above is what I have. Is it a correct way to 
do things or complete idiotic brainfart. Workqueues can sleep so
I thought of the above code, but, was not sure.

And I am not using _interruptible or _interruptible_timeout because
I absolutely want it to wait for the IRQ. Now as such though this 
works I get stack traces with hung task complaining and I have
to set /proc/sys/kernel/hung_task_timeout_secs to 0. And were the IRQ
not generated I do get NMI watchdog hang.

I will accept I have only little knowledge of these things.

Regards,
Victor.