On Fri, Jul 13, 2018 at 09:08:46PM +0800, Robin Gong wrote:
> Add MEMCPY capability for imx-sdma driver.
>
> Signed-off-by: Robin Gong <yibin.g...@nxp.com>
> ---
> drivers/dma/imx-sdma.c | 95
> ++++++++++++++++++++++++++++++++++++++++++++++++--
> 1 file changed, 92 insertions(+), 3 deletions(-)
>
> @@ -1318,6 +1347,63 @@ static struct sdma_desc *sdma_transfer_init(struct
> sdma_channel *sdmac,
> return NULL;
> }
>
> +static struct dma_async_tx_descriptor *sdma_prep_memcpy(
> + struct dma_chan *chan, dma_addr_t dma_dst,
> + dma_addr_t dma_src, size_t len, unsigned long flags)
> +{
> + struct sdma_channel *sdmac = to_sdma_chan(chan);
> + struct sdma_engine *sdma = sdmac->sdma;
> + int channel = sdmac->channel;
> + size_t count;
> + int i = 0, param;
> + struct sdma_buffer_descriptor *bd;
> + struct sdma_desc *desc;
> +
> + if (!chan || !len)
> + return NULL;
> +
> + dev_dbg(sdma->dev, "memcpy: %pad->%pad, len=%zu, channel=%d.\n",
> + &dma_src, &dma_dst, len, channel);
> +
> + desc = sdma_transfer_init(sdmac, DMA_MEM_TO_MEM,
> + len / SDMA_BD_MAX_CNT + 1);
> + if (!desc)
> + return NULL;
> +
> + do {
> + count = min_t(size_t, len, SDMA_BD_MAX_CNT);
> + bd = &desc->bd[i];
> + bd->buffer_addr = dma_src;
> + bd->ext_buffer_addr = dma_dst;
> + bd->mode.count = count;
> + desc->chn_count += count;
> + /* align with sdma->dma_device.copy_align: 4bytes */
> + bd->mode.command = 0;
> +
> + dma_src += count;
> + dma_dst += count;
> + len -= count;
> + i++;
NACK.
Please actually look at your code and find out where you do unaligned DMA
accesses. Hint: What happens when this loop body is executed more than once?
Sascha
> +
> + param = BD_DONE | BD_EXTD | BD_CONT;
> + /* last bd */
> + if (!len) {
> + param |= BD_INTR;
> + param |= BD_LAST;
> + param &= ~BD_CONT;
> + }
> +
> + dev_dbg(sdma->dev, "entry %d: count: %zd dma: 0x%x %s%s\n",
> + i, count, bd->buffer_addr,
> + param & BD_WRAP ? "wrap" : "",
> + param & BD_INTR ? " intr" : "");
> +
> + bd->mode.status = param;
> + } while (len);
> +
--
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