From mboxrd@z Thu Jan  1 00:00:00 1970
From: tglx@linutronix.de (Thomas Gleixner)
Date: Fri, 20 May 2011 15:19:44 +0200 (CEST)
Subject: [PATCH] mfd wm8350: allocate irq descs dynamically
In-Reply-To: <20110520130721.GD10403@pengutronix.de>
References: <1305878365-827-1-git-send-email-s.hauer@pengutronix.de>
	<1305878365-827-3-git-send-email-s.hauer@pengutronix.de>
	<alpine.LFD.2.02.1105201451160.3078@ionos>
	<20110520130721.GD10403@pengutronix.de>
Message-ID: <alpine.LFD.2.02.1105201518030.3078@ionos>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

On Fri, 20 May 2011, Sascha Hauer wrote:

> On Fri, May 20, 2011 at 02:52:28PM +0200, Thomas Gleixner wrote:
> > On Fri, 20 May 2011, Sascha Hauer wrote:
> > > @@ -500,7 +500,17 @@ int wm8350_irq_init(struct wm8350 *wm8350, int irq,
> > >  
> > >  	mutex_init(&wm8350->irq_lock);
> > >  	wm8350->chip_irq = irq;
> > > -	wm8350->irq_base = pdata->irq_base;
> > 
> > Keeping this line would save you the else path :)
> 
> Right.
> 
> > 
> > > +
> > > +	if (!pdata->irq_base) {
> > > +		wm8350->irq_base = irq_alloc_descs(-1, 0, ARRAY_SIZE(wm8350_irqs), 0);
> > > +		if (wm8350->irq_base < 0) {
> > > +			dev_warn(wm8350->dev, "Allocating irqs failed with %d\n",
> > > +				wm8350->irq_base);
> > > +			return 0;
> > 
> >   Hmm, return 0 on failure ?
> 
> This function does this elsewhere aswell. The driver continues without
> interrupt support in this case.

Fair enough.
 
> Looking at the driver again I wonder that it does not call
> irq_set_chained_handler but request_threaded_irq for its chained
> handler. Is it ok to do so or even prefered?

It's ok and done on purpose. See the comment above the interrupt
handler function:

* This is a threaded IRQ handler so can access I2C/SPI. ...

Thanks,

	tglx