[PATCH v3 8/9] PCI: epf-mhi: Use dmaengine_prep_config_single() to simplify code

[Manivannan Sadhasivam]

On Mon, Jan 05, 2026 at 05:46:58PM -0500, Frank Li wrote:
> Use dmaengine_prep_config_single() to simplify
> pci_epf_mhi_edma_read[_sync]() and pci_epf_mhi_edma_write[_sync]().
> 
> No functional change.
> 
> Tested-by: Niklas Cassel <cassel at kernel.org>
> Signed-off-by: Frank Li <Frank.Li at nxp.com>

Acked-by: Manivannan Sadhasivam <mani at kernel.org>

- Mani

> ---
> Keep mutex lock because sync with other function.
> ---
>  drivers/pci/endpoint/functions/pci-epf-mhi.c | 52 +++++++++-------------------
>  1 file changed, 16 insertions(+), 36 deletions(-)
> 
> diff --git a/drivers/pci/endpoint/functions/pci-epf-mhi.c b/drivers/pci/endpoint/functions/pci-epf-mhi.c
> index 6643a88c7a0ce38161bc6253c09d29f1c36ba394..0bf51fd467395182161555f83aa78f3839e36773 100644
> --- a/drivers/pci/endpoint/functions/pci-epf-mhi.c
> +++ b/drivers/pci/endpoint/functions/pci-epf-mhi.c
> @@ -328,12 +328,6 @@ static int pci_epf_mhi_edma_read(struct mhi_ep_cntrl *mhi_cntrl,
>  	config.direction = DMA_DEV_TO_MEM;
>  	config.src_addr = buf_info->host_addr;
>  
> -	ret = dmaengine_slave_config(chan, &config);
> -	if (ret) {
> -		dev_err(dev, "Failed to configure DMA channel\n");
> -		goto err_unlock;
> -	}
> -
>  	dst_addr = dma_map_single(dma_dev, buf_info->dev_addr, buf_info->size,
>  				  DMA_FROM_DEVICE);
>  	ret = dma_mapping_error(dma_dev, dst_addr);
> @@ -342,9 +336,10 @@ static int pci_epf_mhi_edma_read(struct mhi_ep_cntrl *mhi_cntrl,
>  		goto err_unlock;
>  	}
>  
> -	desc = dmaengine_prep_slave_single(chan, dst_addr, buf_info->size,
> -					   DMA_DEV_TO_MEM,
> -					   DMA_CTRL_ACK | DMA_PREP_INTERRUPT);
> +	desc = dmaengine_prep_config_single(chan, dst_addr, buf_info->size,
> +					    DMA_DEV_TO_MEM,
> +					    DMA_CTRL_ACK | DMA_PREP_INTERRUPT,
> +					    &config);
>  	if (!desc) {
>  		dev_err(dev, "Failed to prepare DMA\n");
>  		ret = -EIO;
> @@ -399,12 +394,6 @@ static int pci_epf_mhi_edma_write(struct mhi_ep_cntrl *mhi_cntrl,
>  	config.direction = DMA_MEM_TO_DEV;
>  	config.dst_addr = buf_info->host_addr;
>  
> -	ret = dmaengine_slave_config(chan, &config);
> -	if (ret) {
> -		dev_err(dev, "Failed to configure DMA channel\n");
> -		goto err_unlock;
> -	}
> -
>  	src_addr = dma_map_single(dma_dev, buf_info->dev_addr, buf_info->size,
>  				  DMA_TO_DEVICE);
>  	ret = dma_mapping_error(dma_dev, src_addr);
> @@ -413,9 +402,10 @@ static int pci_epf_mhi_edma_write(struct mhi_ep_cntrl *mhi_cntrl,
>  		goto err_unlock;
>  	}
>  
> -	desc = dmaengine_prep_slave_single(chan, src_addr, buf_info->size,
> -					   DMA_MEM_TO_DEV,
> -					   DMA_CTRL_ACK | DMA_PREP_INTERRUPT);
> +	desc = dmaengine_prep_config_single(chan, src_addr, buf_info->size,
> +					    DMA_MEM_TO_DEV,
> +					    DMA_CTRL_ACK | DMA_PREP_INTERRUPT,
> +					    &config);
>  	if (!desc) {
>  		dev_err(dev, "Failed to prepare DMA\n");
>  		ret = -EIO;
> @@ -502,12 +492,6 @@ static int pci_epf_mhi_edma_read_async(struct mhi_ep_cntrl *mhi_cntrl,
>  	config.direction = DMA_DEV_TO_MEM;
>  	config.src_addr = buf_info->host_addr;
>  
> -	ret = dmaengine_slave_config(chan, &config);
> -	if (ret) {
> -		dev_err(dev, "Failed to configure DMA channel\n");
> -		goto err_unlock;
> -	}
> -
>  	dst_addr = dma_map_single(dma_dev, buf_info->dev_addr, buf_info->size,
>  				  DMA_FROM_DEVICE);
>  	ret = dma_mapping_error(dma_dev, dst_addr);
> @@ -516,9 +500,10 @@ static int pci_epf_mhi_edma_read_async(struct mhi_ep_cntrl *mhi_cntrl,
>  		goto err_unlock;
>  	}
>  
> -	desc = dmaengine_prep_slave_single(chan, dst_addr, buf_info->size,
> -					   DMA_DEV_TO_MEM,
> -					   DMA_CTRL_ACK | DMA_PREP_INTERRUPT);
> +	desc = dmaengine_prep_config_single(chan, dst_addr, buf_info->size,
> +					    DMA_DEV_TO_MEM,
> +					    DMA_CTRL_ACK | DMA_PREP_INTERRUPT,
> +					    &config);
>  	if (!desc) {
>  		dev_err(dev, "Failed to prepare DMA\n");
>  		ret = -EIO;
> @@ -581,12 +566,6 @@ static int pci_epf_mhi_edma_write_async(struct mhi_ep_cntrl *mhi_cntrl,
>  	config.direction = DMA_MEM_TO_DEV;
>  	config.dst_addr = buf_info->host_addr;
>  
> -	ret = dmaengine_slave_config(chan, &config);
> -	if (ret) {
> -		dev_err(dev, "Failed to configure DMA channel\n");
> -		goto err_unlock;
> -	}
> -
>  	src_addr = dma_map_single(dma_dev, buf_info->dev_addr, buf_info->size,
>  				  DMA_TO_DEVICE);
>  	ret = dma_mapping_error(dma_dev, src_addr);
> @@ -595,9 +574,10 @@ static int pci_epf_mhi_edma_write_async(struct mhi_ep_cntrl *mhi_cntrl,
>  		goto err_unlock;
>  	}
>  
> -	desc = dmaengine_prep_slave_single(chan, src_addr, buf_info->size,
> -					   DMA_MEM_TO_DEV,
> -					   DMA_CTRL_ACK | DMA_PREP_INTERRUPT);
> +	desc = dmaengine_prep_config_single(chan, src_addr, buf_info->size,
> +					    DMA_MEM_TO_DEV,
> +					    DMA_CTRL_ACK | DMA_PREP_INTERRUPT,
> +					    &config);
>  	if (!desc) {
>  		dev_err(dev, "Failed to prepare DMA\n");
>  		ret = -EIO;
> 
> -- 
> 2.34.1
> 

-- 
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