[PATCH 8/8] dmaengine/dw_dmac: Add support for DMA_SLAVE_CONFIG

Viresh Kumar viresh.kumar at st.com
Mon Jan 16 06:42:29 EST 2012


On 1/16/2012 3:20 PM, Viresh KUMAR wrote:
> +	/*
> +	 * Fix sconfig's burst size according to dw_dmac. We need to convert
> +	 * them as: 1 -> 0, 2 -> 1, 4 -> 2, 8 -> 3, 16 -> 4.
> +	 *
> +	 * This can be done by findiding least significant bit set: n & (n - 1)
> +	 */
> +	sconfig->src_maxburst &= sconfig->src_maxburst - 1;
> +	sconfig->dst_maxburst &= sconfig->dst_maxburst - 1;

Perhaps, this looks incorrect. It will always return 0. :(
Can somebody suggest any inbuild function to do this, i think

find_next_bit(sconfig->src_maxburst, sizeof(sconfig->src_maxburst), 0)

will do it.

-- 
viresh



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