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From: Kumar Gala <galak@kernel.crashing.org>
Subject: Re: IRQs in i2c-mpc.c
Date: Sat, 10 Nov 2007 17:09:56 -0600
To: Jon Smirl <jonsmirl@gmail.com>
Cc: PowerPC dev list <Linuxppc-dev@ozlabs.org>
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On Nov 10, 2007, at 1:44 PM, Jon Smirl wrote:

> I'm doing final clean up the i2c open firmware support. What is the
> intention of this code? Is it meant for a missing IRQ attribute to
> return a zero and not get an IRQ for the device? Does the device
> function without an IRQ? If so, it needs a comment explaining things.
> Otherwise IRQ of zero should be an error.
>
> 	i2c->irq = irq_of_parse_and_map(op->node, 0);
> 	if (i2c->irq <= 0) {
> 		result = -ENXIO;
> 		goto fail_irq;
> 	}
> 	
> 	if (i2c->irq != 0)
> 		if ((result = request_irq(i2c->irq, mpc_i2c_isr,
> 					  	IRQF_SHARED, "i2c-mpc", i2c)) < 0) {
> 			printk(KERN_ERR "i2c-mpc - failed to attach interrupt\n");
> 			goto fail_irq;
> 		}

Looking at the current driver it looks like we could get ride of if  
check since the previous code checked the return of platform_get_irq().

- k