On Fri, Jan 20, 2017 at 04:32:48PM +0100, Andrea Merello wrote:
> The maximumum trasfer length is currently hardcoded in the driver, but
> it depends by how the soft-IP is actually configuried.
/s/configuried/configured
> This seems to affect also max possible length for SG transfers.
>
> This patch introduce a new DT property in order to operate with proper
> maximum trasfer length.
>
> Signed-off-by: Andrea Merello <andrea.merello@xxxxxxxxx>
> ---
> drivers/dma/xilinx/xilinx_dma.c | 22 ++++++++++++++++------
> 1 file changed, 16 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/dma/xilinx/xilinx_dma.c b/drivers/dma/xilinx/xilinx_dma.c
> index 33c0949..cbd8d8c 100644
> --- a/drivers/dma/xilinx/xilinx_dma.c
> +++ b/drivers/dma/xilinx/xilinx_dma.c
> @@ -409,6 +409,7 @@ struct xilinx_dma_device {
> struct clk *rxs_clk;
> u32 nr_channels;
> u32 chan_id;
> + int max_transfer;
> };
>
> /* Macros */
> @@ -1764,8 +1765,8 @@ static struct dma_async_tx_descriptor *xilinx_dma_prep_slave_sg(
> * the next chuck start address is aligned
> */
> copy = sg_dma_len(sg) - sg_used;
> - if (copy > XILINX_DMA_MAX_TRANS_LEN)
> - copy = XILINX_DMA_MAX_TRANS_LEN &
> + if (copy > chan->xdev->max_transfer)
> + copy = chan->xdev->max_transfer &
> chan->copy_mask;
>
> hw = &segment->hw;
> @@ -1875,8 +1876,8 @@ static struct dma_async_tx_descriptor *xilinx_dma_prep_dma_cyclic(
> * the next chuck start address is aligned
> */
> copy = period_len - sg_used;
> - if (copy > XILINX_DMA_MAX_TRANS_LEN)
> - copy = XILINX_DMA_MAX_TRANS_LEN &
> + if (copy > chan->xdev->max_transfer)
> + copy = chan->xdev->max_transfer &
> chan->copy_mask;
>
> hw = &segment->hw;
> @@ -2534,7 +2535,7 @@ static int xilinx_dma_probe(struct platform_device *pdev)
> struct xilinx_dma_device *xdev;
> struct device_node *child, *np = pdev->dev.of_node;
> struct resource *io;
> - u32 num_frames, addr_width;
> + u32 num_frames, addr_width, lenreg_width;
> int i, err;
>
> /* Allocate and initialize the DMA engine structure */
> @@ -2565,8 +2566,17 @@ static int xilinx_dma_probe(struct platform_device *pdev)
> return PTR_ERR(xdev->regs);
>
> /* Retrieve the DMA engine properties from the device tree */
> - if (xdev->dma_config->dmatype == XDMA_TYPE_AXIDMA)
> + if (xdev->dma_config->dmatype == XDMA_TYPE_AXIDMA) {
> xdev->mcdma = of_property_read_bool(node, "xlnx,mcdma");
> + err = of_property_read_u32(node, "xlnx,lengthregwidth",
> + &lenreg_width);
ah you are using a property for this, where is this added??
> + if (err < 0) {
> + dev_err(xdev->dev,
> + "missing xlnx,lengthregwidth property\n");
> + return err;
> + }
> + xdev->max_transfer = GENMASK(lenreg_width, 0);
> + }
>
> if (xdev->dma_config->dmatype == XDMA_TYPE_VDMA) {
> err = of_property_read_u32(node, "xlnx,num-fstores",
> --
> 2.7.4
>
--
~Vinod
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