Re: [PATCH] MTD: atmel_nand: Add DMA support to access Nandflash

From: Ryan Mallon
Date: Mon Jan 17 2011 - 16:35:18 EST


On 01/17/2011 08:20 PM, Hong Xu wrote:
> Some SAM9 chips have the ability to perform DMA between CPU and SMC controller.
> This patch adds DMA support for SAM9RL, SAM9G45, SSAM9G46,AM9M10, SAM9M11.
>
> Signed-off-by: Hong Xu <hong.xu@xxxxxxxxx>
> ---

One more comment:

> + if (cpu_has_dma() && use_dma) {
> + dma_cap_mask_t mask;
> +
> + dma_cap_zero(mask);
> + dma_cap_set(DMA_MEMCPY, mask);
> + host->dma_chan = dma_request_channel(mask, 0, NULL);
> +
> + if (!host->dma_chan) {
> + dev_err(host->dev, "Failed to request DMA channel\n");
> + host->dma_ready = 0;

Because host is kzalloc'ed above, you do not need to set host->dma_ready
to zero here.

~Ryan

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