Subject: Re: [PATCH 2/5] net: mvneta: fix the wrong function to unmap rx buf

From: Gregory CLEMENT <[email-masked]>
Date: Wed, 29 Aug 2018 11:21:12 +0200

Hi Jisheng,
 
 On mer., août 29 2018, Jisheng Zhang <[email-masked]> wrote:

> Commit 7e47fd84b56b ("net: mvneta: Allocate page for the descriptor")
> always allocate one page for each rx descriptor, so the rx is mapped
> with dmap_map_page() now, but the unmap routine isn't updated at the
> same time.
>
> Fix this by using dma_unmap_page() in corresponding places.
>
> Fixes: 7e47fd84b56b ("net: mvneta: Allocate page for the descriptor")
> Signed-off-by: Jisheng Zhang <[email-masked]>
> ---
>  drivers/net/ethernet/marvell/mvneta.c | 14 +++++++-------
>  1 file changed, 7 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/net/ethernet/marvell/mvneta.c b/drivers/net/ethernet/marvell/mvneta.c
> index 0ce94f6587a5..d9206094fce3 100644
> --- a/drivers/net/ethernet/marvell/mvneta.c
> +++ b/drivers/net/ethernet/marvell/mvneta.c
> @@ -1890,8 +1890,9 @@ static void mvneta_rxq_drop_pkts(struct mvneta_port *pp,
>  		if (!data || !(rx_desc->buf_phys_addr))
>  			continue;
>  
> -		dma_unmap_single(pp->dev->dev.parent, rx_desc->buf_phys_addr,
> -				 MVNETA_RX_BUF_SIZE(pp->pkt_size), DMA_FROM_DEVICE);
> +		dma_unmap_page(pp->dev->dev.parent, rx_desc->buf_phys_addr,
> +			       MVNETA_RX_BUF_SIZE(pp->pkt_size),
> +			       DMA_FROM_DEVICE);
>  		__free_page(data);
>  	}
>  }
This one can be called when the allocation is done in with HWBM in this
case which use a dma_map_single.

Gregory

> @@ -2008,8 +2009,8 @@ static int mvneta_rx_swbm(struct napi_struct *napi,
>  				skb_add_rx_frag(rxq->skb, frag_num, page,
>  						frag_offset, frag_size,
>  						PAGE_SIZE);
> -				dma_unmap_single(dev->dev.parent, phys_addr,
> -						 PAGE_SIZE, DMA_FROM_DEVICE);
> +				dma_unmap_page(dev->dev.parent, phys_addr,
> +					       PAGE_SIZE, DMA_FROM_DEVICE);
>  				rxq->left_size -= frag_size;
>  			}
>  		} else {
> @@ -2039,9 +2040,8 @@ static int mvneta_rx_swbm(struct napi_struct *napi,
>  						frag_offset, frag_size,
>  						PAGE_SIZE);
>  
> -				dma_unmap_single(dev->dev.parent, phys_addr,
> -						 PAGE_SIZE,
> -						 DMA_FROM_DEVICE);
> +				dma_unmap_page(dev->dev.parent, phys_addr,
> +					       PAGE_SIZE, DMA_FROM_DEVICE);
>  
>  				rxq->left_size -= frag_size;
>  			}
> -- 
> 2.18.0
>
>
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-- 
Gregory Clement, Bootlin
Embedded Linux and Kernel engineering
http://bootlin.com