RE: [PATCH 2/7] usb: chipidea: add freescale imx28 special write register method

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From: Peter Chen
...
> +#ifdef 
> +static inline void imx28_ci_writel(u32 val, volatile void __iomem *addr)
> +{
> +	__asm__ ("swp %0, %0, [%1]" : : "r"(val), "r"(addr));
> +}
> +#else
> +static inline void imx28_ci_writel(u32 val, volatile void __iomem *addr)
> +{
> +}
> +#endif
> +
> +static inline void __hw_write(struct ci_hdrc *ci, u32 val,
> +		void __iomem *addr)
> +{
> +	if (ci->imx28_write_fix)
> +		imx28_ci_writel(val, addr);
> +	else
> +		iowrite32(val, addr);
> +}
> +

This code ought to be defensive against 'imx28_write_fix' being
set when the kernel isn't compiled with CONFIG_SOC_IMX28.
This can easily be done by changing the #else block to do an iowrite().

It is worth looking to see if the compiler manages to optimise away
the 'if' test in this case. It might do better if a #define is used
instead of the inline function.

	David



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