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

[Andy Shevchenko]

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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