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

From: Stanimir Vabanov
Date: Fri Mar 07 2014 - 17:30:05 EST


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
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