| Message ID | 4759713.2ulGRKsd9L@wasted.cogentembedded.com |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
Hello. On 7/15/2015 12:56 AM, Sergei Shtylyov wrote: > First, dma_sync_single_for_cpu() shouldn't have been called in the first place > (it's a streaming DMA API). dma_unmap_single() should have been called instead. ^ Oops, I meant comma here. > Second, dma_unmap_single() call after handing the buffer to napi_gro_receive() > makes little sense. Moreover, 'desc->dptr' may not be valid at this point... > Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com> > > --- > The patch is against Dave Miller's 'net.git' repo. > Don't know why I missed this DMA API misuse while working on the driver. :-< Dave, do you want me to resend the patch with fixed up changelog? > drivers/net/ethernet/renesas/ravb_main.c | 10 +++------- > 1 file changed, 3 insertions(+), 7 deletions(-) > > Index: net/drivers/net/ethernet/renesas/ravb_main.c > =================================================================== > --- net.orig/drivers/net/ethernet/renesas/ravb_main.c > +++ net/drivers/net/ethernet/renesas/ravb_main.c [...] > @@ -584,9 +583,6 @@ static bool ravb_rx(struct net_device *n > if (!skb) > break; /* Better luck next round. */ > ravb_set_buffer_align(skb); > - dma_unmap_single(&ndev->dev, le32_to_cpu(desc->dptr), > - ALIGN(PKT_BUF_SZ, 16), > - DMA_FROM_DEVICE); > dma_addr = dma_map_single(&ndev->dev, skb->data, > le16_to_cpu(desc->ds_cc), > DMA_FROM_DEVICE); WBR, Sergei -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 7/15/2015 1:45 PM, Sergei Shtylyov wrote: >> First, dma_sync_single_for_cpu() shouldn't have been called in the first place >> (it's a streaming DMA API). dma_unmap_single() should have been called instead. > ^ > Oops, I meant comma here. >> Second, dma_unmap_single() call after handing the buffer to napi_gro_receive() >> makes little sense. > Moreover, 'desc->dptr' may not be valid at this point... >> Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com> >> --- >> The patch is against Dave Miller's 'net.git' repo. >> Don't know why I missed this DMA API misuse while working on the driver. :-< > Dave, do you want me to resend the patch with fixed up changelog? Oops, forgot to CC Dave. :-( WBR, Sergei -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
From: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com> Date: Wed, 15 Jul 2015 00:56:52 +0300 > First, dma_sync_single_for_cpu() shouldn't have been called in the first place > (it's a streaming DMA API). dma_unmap_single() should have been called instead. > Second, dma_unmap_single() call after handing the buffer to napi_gro_receive() > makes little sense. > > Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com> Applied with fixed up commit log message, thanks. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Index: net/drivers/net/ethernet/renesas/ravb_main.c =================================================================== --- net.orig/drivers/net/ethernet/renesas/ravb_main.c +++ net/drivers/net/ethernet/renesas/ravb_main.c @@ -543,10 +543,9 @@ static bool ravb_rx(struct net_device *n skb = priv->rx_skb[q][entry]; priv->rx_skb[q][entry] = NULL; - dma_sync_single_for_cpu(&ndev->dev, - le32_to_cpu(desc->dptr), - ALIGN(PKT_BUF_SZ, 16), - DMA_FROM_DEVICE); + dma_unmap_single(&ndev->dev, le32_to_cpu(desc->dptr), + ALIGN(PKT_BUF_SZ, 16), + DMA_FROM_DEVICE); get_ts &= (q == RAVB_NC) ? RAVB_RXTSTAMP_TYPE_V2_L2_EVENT : ~RAVB_RXTSTAMP_TYPE_V2_L2_EVENT; @@ -584,9 +583,6 @@ static bool ravb_rx(struct net_device *n if (!skb) break; /* Better luck next round. */ ravb_set_buffer_align(skb); - dma_unmap_single(&ndev->dev, le32_to_cpu(desc->dptr), - ALIGN(PKT_BUF_SZ, 16), - DMA_FROM_DEVICE); dma_addr = dma_map_single(&ndev->dev, skb->data, le16_to_cpu(desc->ds_cc), DMA_FROM_DEVICE);
First, dma_sync_single_for_cpu() shouldn't have been called in the first place (it's a streaming DMA API). dma_unmap_single() should have been called instead. Second, dma_unmap_single() call after handing the buffer to napi_gro_receive() makes little sense. Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com> --- The patch is against Dave Miller's 'net.git' repo. Don't know why I missed this DMA API misuse while working on the driver. :-< drivers/net/ethernet/renesas/ravb_main.c | 10 +++------- 1 file changed, 3 insertions(+), 7 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html