[PATCH 4/7] ARM: mx25: Retrieve IIM base from dt

[linux@arm.linux.org.uk (Russell King - ARM Linux)]

On Wed, Mar 11, 2015 at 09:43:52AM -0300, Fabio Estevam wrote:
> +	void __iomem *iim_base;
> +	struct device_node *np;
> +
> +	np = of_find_compatible_node(NULL, NULL, "fsl,imx25-iim");
> +	iim_base = of_iomap(np, 0);
> +	WARN_ON(!iim_base);
> +	rev = readl(iim_base + MXC_IIMSREV);
> +	iounmap(iim_base);

Is there much point to that WARN_ON()?  Are you avoiding the political
BUG_ON(!iim_base) ? :)

Since a NULL pointer there will lead to a NULL pointer dereference, it's
silly to use WARN_ON() there - we'll get a backtrace etc from the WARN_ON
followed immediately by an oops dump due to the readl(), crashing the
kernel.

Better to just use BUG_ON() and only get one set of diagnostics.

-- 
FTTC broadband for 0.8mile line: currently at 10.5Mbps down 400kbps up
according to speedtest.net.