From mboxrd@z Thu Jan  1 00:00:00 1970
From: Thomas Gleixner <tglx@linutronix.de>
Subject: Re: [PATCH] tty: serial: sc16is7xx: implemented our own oneshot-like
 handling
Date: Sun, 13 Mar 2016 11:25:05 +0100 (CET)
Message-ID: <alpine.DEB.2.11.1603131103020.3657@nanos>
References: <1457692476-19082-1-git-send-email-sean.nyekjaer@prevas.dk>
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To: Sean Nyekjaer <sean.nyekjaer@prevas.dk>
Cc: linux-serial@vger.kernel.org, Josh Cartwright <joshc@ni.com>, Greg Kroah-Hartman <gregkh@linuxfoundation.org>, linux-rt-users@vger.kernel.org, Jon Ringle <jringle@gridpoint.com>
List-Id: linux-serial@vger.kernel.org

On Fri, 11 Mar 2016, Sean Nyekjaer wrote:

>  static irqreturn_t sc16is7xx_irq(int irq, void *dev_id)
>  {
>  	struct sc16is7xx_port *s = (struct sc16is7xx_port *)dev_id;
> +	int i;
> +
> +	for (i = 0; i < s->devtype->nr_uart; ++i)
> +		disable_irq_nosync(s->p[i].port.irq);

Aside of the lack of a changelog. This is completely bogus. You disable the
same interrupt a gazillion of times. 

>  	queue_kthread_work(&s->kworker, &s->irq_work);

This driver should use a threaded interrupt instead of trying to emulate it
via dis/enable_irq and a worker thread.

Then you simply call c16is7xx_port_irq() right from the interrupt routine and
the core code deals with the interrupt mask/unmask automatically.

Thanks,

	tglx