[Q] block / zynq: DMA bouncing

Russell King - ARM Linux linux at arm.linux.org.uk
Tue Jan 28 08:48:27 EST 2014


On Tue, Jan 28, 2014 at 02:28:28PM +0100, Guennadi Liakhovetski wrote:
> +static void __init zynq_memory_init(void)
> +{
> +	/*
> +	 * Reserve the 0-0x4000 addresses (before page tables and kernel)
> +	 * which can't be used for DMA
> +	 */
> +	if (!__pa(PAGE_OFFSET))
> +		memblock_reserve(0, 0x4000);

Or maybe this:

	memblock_reserve(__pa(PAGE_OFFSET), __pa(swapper_pg_dir));

since that's actually what you mean here.

-- 
FTTC broadband for 0.8mile line: 5.8Mbps down 500kbps up.  Estimation
in database were 13.1 to 19Mbit for a good line, about 7.5+ for a bad.
Estimate before purchase was "up to 13.2Mbit".



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