Re: [PATCH v2 2/6] ntb: Use consistent DMA attributes when freeing DMA mappings

[Dave Jiang]

On 4/30/26 11:35 PM, Leon Romanovsky wrote:
> From: Leon Romanovsky <leonro@xxxxxxxxxx>
> 
> The counterpart of dma_alloc_attrs() is dma_free_attrs(), which must
> receive the same DMA attributes used during allocation. The code
> previously used dma_free_coherent(), which does not accept or apply any
> DMA attributes.
> 
> Fixes: 061a785a114f ("ntb: Force physically contiguous allocation of rx ring buffers")
> Signed-off-by: Leon Romanovsky <leonro@xxxxxxxxxx>

Reviewed-by: Dave Jiang <dave.jiang@xxxxxxxxx>


> ---
>  drivers/ntb/ntb_transport.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/ntb/ntb_transport.c b/drivers/ntb/ntb_transport.c
> index 771eb7d9f4356..f59f926d4bfaa 100644
> --- a/drivers/ntb/ntb_transport.c
> +++ b/drivers/ntb/ntb_transport.c
> @@ -766,8 +766,8 @@ static void ntb_free_mw(struct ntb_transport_ctx *nt, int num_mw)
>  		return;
>  
>  	ntb_mw_clear_trans(nt->ndev, PIDX, num_mw);
> -	dma_free_coherent(dma_dev, mw->alloc_size,
> -			  mw->alloc_addr, mw->original_dma_addr);
> +	dma_free_attrs(dma_dev, mw->alloc_size, mw->alloc_addr,
> +		       mw->original_dma_addr, DMA_ATTR_FORCE_CONTIGUOUS);
>  	mw->xlat_size = 0;
>  	mw->buff_size = 0;
>  	mw->alloc_size = 0;
> @@ -828,8 +828,8 @@ static int ntb_alloc_mw_buffer(struct ntb_transport_mw *mw,
>  	return 0;
>  
>  err:
> -	dma_free_coherent(ntb_dev, mw->alloc_size, alloc_addr, dma_addr);
> -
> +	dma_free_attrs(ntb_dev, mw->alloc_size, alloc_addr, dma_addr,
> +		       DMA_ATTR_FORCE_CONTIGUOUS);
>  	return rc;
>  }
>  
>