[PATCH v3 4/4] mmc: atmel-mci: use probe deferring if dma controller is not ready yet

Russell King - ARM Linux linux at arm.linux.org.uk
Fri Nov 28 06:19:03 PST 2014


Let's look at the resulting code:

On Fri, Nov 28, 2014 at 03:08:06PM +0100, Ludovic Desroches wrote:
> +static int atmci_configure_dma(struct atmel_mci *host)
>  {
> +	int ret = 0;
>  
> +	host->dma.chan = dma_request_slave_channel_reason(&host->pdev->dev, "rxtx");
> +	if (IS_ERR(host->dma.chan))
> +		return PTR_ERR(host->dma.chan);
> +
> +	dev_info(&host->pdev->dev, "using %s for DMA transfers\n",
> +		 dma_chan_name(host->dma.chan));
> +
> +	host->dma_conf.src_addr = host->mapbase + ATMCI_RDR;
> +	host->dma_conf.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
> +	host->dma_conf.src_maxburst = 1;
> +	host->dma_conf.dst_addr = host->mapbase + ATMCI_TDR;
> +	host->dma_conf.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
> +	host->dma_conf.dst_maxburst = 1;
> +	host->dma_conf.device_fc = false;
> +
> +	return ret;
>  }

I think you can clean this up a little further - what do you notice
about the value of "ret" here?

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