Subject: [Patch v8 2/2] dmaengine: add Qualcomm BAM dma driver

From: [email-masked] (Stanimir Vabanov)
Date: Sat, 08 Mar 2014 00:29:49 +0200

Hi Andy,

Thanks for the patch.

<snip>

> +#define BAM_IRQ_SRCS_EE(pipe)		(0x0800 + ((pipe) * 0x80))
> +#define BAM_IRQ_SRCS_MSK_EE(pipe)	(0x0804 + ((pipe) * 0x80))

s/pipe/ee ?

<snip>

> +struct bam_chan {
> +	struct virt_dma_chan vc;
> +
> +	struct bam_device *bdev;
> +
> +	/* configuration from device tree */
> +	u32 id;
> +	u32 ee;
> +

do we need per channel ee? I'm asking because failed to find references
to it.

> +	struct bam_async_desc *curr_txd;	/* current running dma */
> +
> +	/* runtime configuration */
> +	struct dma_slave_config slave;
> +
> +	/* fifo storage */
> +	struct bam_desc_hw *fifo_virt;
> +	dma_addr_t fifo_phys;
> +
> +	/* fifo markers */
> +	unsigned short head;		/* start of active descriptor entries */
> +	unsigned short tail;		/* end of active descriptor entries */
> +
> +	unsigned int initialized;	/* is the channel hw initialized? */
> +	unsigned int paused;		/* is the channel paused? */
> +	unsigned int reconfigure;	/* new slave config? */
> +
> +	struct list_head node;
> +};
> +

<snip>

> +
> +/**
> + * bam_alloc_chan - Allocate channel resources for DMA channel.
> + * @chan: specified channel
> + *
> + * This function allocates the FIFO descriptor memory
> + */
> +static int bam_alloc_chan(struct dma_chan *chan)
> +{
> +	struct bam_chan *bchan = to_bam_chan(chan);
> +	struct bam_device *bdev = bchan->bdev;
> +

you could invert the logic and avoid extra indentation.
	if (bchan->fifo_virt)
		return 0;

> +	/* allocate FIFO descriptor space, but only if necessary */
> +	if (!bchan->fifo_virt) {
> +		bchan->fifo_virt = dma_alloc_writecombine(bdev->dev,
> +					BAM_DESC_FIFO_SIZE, &bchan->fifo_phys,
> +					GFP_KERNEL);
> +
> +		if (!bchan->fifo_virt) {
> +			dev_err(bdev->dev, "Failed to allocate desc fifo\n");
> +			return -ENOMEM;
> +		}
> +	}
> +
> +	return 0;
> +}
> +

<snip>

regards,
Stan