Re: [PATCH v4 3/3] dma: imx-sdma: reorg code to make code clean

From: Andy Shevchenko
Date: Tue Oct 21 2014 - 05:39:41 EST


On Tue, 2014-10-21 at 09:09 +0800, Robin Gong wrote:
> code reorg for transfer prepare and bus width check.

Fix style of commit message.

>
> Signed-off-by: Robin Gong <b38343@xxxxxxxxxxxxx>
> ---
> drivers/dma/imx-sdma.c | 127 +++++++++++++++++++++++--------------------------
> 1 file changed, 60 insertions(+), 67 deletions(-)
>
> diff --git a/drivers/dma/imx-sdma.c b/drivers/dma/imx-sdma.c
> index 7e8aa2d..b0365c2 100644
> --- a/drivers/dma/imx-sdma.c
> +++ b/drivers/dma/imx-sdma.c
> @@ -1026,6 +1026,52 @@ static void sdma_free_chan_resources(struct dma_chan *chan)
> clk_disable(sdma->clk_ahb);
> }
>
> +static int sdma_transfer_init(struct sdma_channel *sdmac,
> + enum dma_transfer_direction direction)
> +{
> + int ret = 0;

Redundant assignment.

> +
> + sdmac->status = DMA_IN_PROGRESS;
> + sdmac->buf_tail = 0;
> + sdmac->flags = 0;
> + sdmac->direction = direction;
> +
> + ret = sdma_load_context(sdmac);
> + if (ret)
> + return ret;
> +
> + sdmac->chn_count = 0;
> +
> + return ret;
> +}
> +
> +static int check_bd_buswidth(struct sdma_buffer_descriptor *bd,
> + struct sdma_channel *sdmac, int count,
> + dma_addr_t dma_dst, dma_addr_t dma_src)
> +{
> + int ret = 0;
> +
> + switch (sdmac->word_size) {
> + case DMA_SLAVE_BUSWIDTH_4_BYTES:
> + bd->mode.command = 0;
> + if ((count | dma_dst | dma_src) & 3)
> + ret = -EINVAL;
> + break;
> + case DMA_SLAVE_BUSWIDTH_2_BYTES:
> + bd->mode.command = 2;
> + if ((count | dma_dst | dma_src) & 1)
> + ret = -EINVAL;
> + break;
> + case DMA_SLAVE_BUSWIDTH_1_BYTE:
> + bd->mode.command = 1;
> + break;
> + default:
> + return -EINVAL;
> + }
> +
> + return ret;
> +}
> +
> 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)
> @@ -1034,7 +1080,7 @@ static struct dma_async_tx_descriptor *sdma_prep_memcpy(
> struct sdma_engine *sdma = sdmac->sdma;
> int channel = sdmac->channel;
> size_t count;
> - int i = 0, param, ret;
> + int i = 0, param;
> struct sdma_buffer_descriptor *bd;
>
> if (!chan || !len || sdmac->status == DMA_IN_PROGRESS)
> @@ -1046,21 +1092,12 @@ static struct dma_async_tx_descriptor *sdma_prep_memcpy(
> goto err_out;
> }
>
> - sdmac->status = DMA_IN_PROGRESS;
> -
> - sdmac->buf_tail = 0;
> -
> dev_dbg(sdma->dev, "memcpy: %pad->%pad, len=%zu, channel=%d.\n",
> &dma_src, &dma_dst, len, channel);
>
> - sdmac->direction = DMA_MEM_TO_MEM;
> -
> - ret = sdma_load_context(sdmac);
> - if (ret)
> + if (sdma_transfer_init(sdmac, DMA_MEM_TO_MEM))
> goto err_out;
>
> - sdmac->chn_count = 0;
> -
> do {
> count = min_t(size_t, len, SDMA_BD_MAX_CNT);
> bd = &sdmac->bd[i];
> @@ -1068,28 +1105,8 @@ static struct dma_async_tx_descriptor *sdma_prep_memcpy(
> bd->ext_buffer_addr = dma_dst;
> bd->mode.count = count;
>
> - if (sdmac->word_size > DMA_SLAVE_BUSWIDTH_4_BYTES) {
> - ret = -EINVAL;
> + if (check_bd_buswidth(bd, sdmac, count, dma_dst, dma_src))
> goto err_out;
> - }
> -
> - switch (sdmac->word_size) {
> - case DMA_SLAVE_BUSWIDTH_4_BYTES:
> - bd->mode.command = 0;
> - if ((count | dma_dst | dma_src) & 3)
> - return NULL;
> - break;
> - case DMA_SLAVE_BUSWIDTH_2_BYTES:
> - bd->mode.command = 2;
> - if ((count | dma_dst | dma_src) & 1)
> - return NULL;
> - break;
> - case DMA_SLAVE_BUSWIDTH_1_BYTE:
> - bd->mode.command = 1;
> - break;
> - default:
> - return NULL;
> - }
>
> dma_src += count;
> dma_dst += count;
> @@ -1141,21 +1158,10 @@ static struct dma_async_tx_descriptor *sdma_prep_sg(
>
> if (sdmac->status == DMA_IN_PROGRESS)
> return NULL;
> - sdmac->status = DMA_IN_PROGRESS;
> -
> - sdmac->flags = 0;
> -
> - sdmac->buf_tail = 0;
>
> dev_dbg(sdma->dev, "setting up %d entries for channel %d.\n",
> src_nents, channel);
>
> - sdmac->direction = direction;
> -
> - ret = sdma_load_context(sdmac);
> - if (ret)
> - goto err_out;
> -
> if (src_nents > NUM_BD) {
> dev_err(sdma->dev, "SDMA channel %d: maximum number of sg exceeded: %d > %d\n",
> channel, src_nents, NUM_BD);
> @@ -1163,7 +1169,9 @@ static struct dma_async_tx_descriptor *sdma_prep_sg(
> goto err_out;
> }
>
> - sdmac->chn_count = 0;
> + if (sdma_transfer_init(sdmac, direction))
> + goto err_out;
> +
> for_each_sg(src_sg, sg_src, src_nents, i) {
> struct sdma_buffer_descriptor *bd = &sdmac->bd[i];
> int param;
> @@ -1187,30 +1195,15 @@ static struct dma_async_tx_descriptor *sdma_prep_sg(
> bd->mode.count = count;
> sdmac->chn_count += count;
>
> - if (sdmac->word_size > DMA_SLAVE_BUSWIDTH_4_BYTES) {
> - ret = -EINVAL;
> + if (direction == DMA_MEM_TO_MEM)
> + ret = check_bd_buswidth(bd, sdmac, count,
> + sg_dst->dma_address,
> + sg_src->dma_address);
> + else
> + ret = check_bd_buswidth(bd, sdmac, count, 0,
> + sg_src->dma_address);
> + if (ret)
> goto err_out;
> - }
> -
> - switch (sdmac->word_size) {
> - case DMA_SLAVE_BUSWIDTH_4_BYTES:
> - bd->mode.command = 0;
> - if ((count | sg_src->dma_address | (sg_dst &&
> - (sg_dst->dma_address))) & 3)
> - return NULL;
> - break;
> - case DMA_SLAVE_BUSWIDTH_2_BYTES:
> - bd->mode.command = 2;
> - if ((count | sg_src->dma_address |
> - (sg_dst && (sg_dst->dma_address))) & 1)
> - return NULL;
> - break;
> - case DMA_SLAVE_BUSWIDTH_1_BYTE:
> - bd->mode.command = 1;
> - break;
> - default:
> - return NULL;
> - }
>
> param = BD_DONE | BD_EXTD | BD_CONT;
>


--
Andy Shevchenko <andriy.shevchenko@xxxxxxxxx>
Intel Finland Oy

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