[PATCH 3/9] ARM: versatile: add DT based PCI detection

Arnd Bergmann arnd at arndb.de
Tue Dec 30 13:37:01 PST 2014


On Tuesday 30 December 2014 13:28:32 Rob Herring wrote:
> From: Rob Herring <robh at kernel.org>
> 
> Disable the Versatile PCI DT node when no PCI backplane is detected. This
> will prevent the Versatile PCI driver from probing when PCI is not
> populated.

Can you explain why the check is done in platform code instead of the PCI
driver probe function itself?

> +	/* Check if PCI backplane is detected */
> +	val = __raw_readl(base + VERSATILE_SYS_PCICTL_OFFSET);
> +	if (val & 1)
> +		goto err;

Using __raw_readl prevents this from working with big-endian kernels, so just
use readl here.

	Arnd



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