| Message ID | 20250122104307.138659-1-dheeraj.linuxdev@gmail.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [net] net: fec: remove unnecessary DMA mapping of TSO header | expand |
On Wed, Jan 22, 2025 at 04:13:07PM +0530, Dheeraj Reddy Jonnalagadda wrote: > The TSO header buffer is pre-allocated DMA memory, so there's no need to > map it again with dma_map_single() in fec_enet_txq_put_hdr_tso(). Remove > this redundant mapping operation. > > Fixes: 79f339125ea3 ("net: fec: Add software TSO support") > Signed-off-by: Dheeraj Reddy Jonnalagadda <dheeraj.linuxdev@gmail.com> > --- > drivers/net/ethernet/freescale/fec_main.c | 9 --------- > 1 file changed, 9 deletions(-) > > diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c > index 68725506a095..039de4c5044e 100644 > --- a/drivers/net/ethernet/freescale/fec_main.c > +++ b/drivers/net/ethernet/freescale/fec_main.c > @@ -805,15 +805,6 @@ fec_enet_txq_put_hdr_tso(struct fec_enet_priv_tx_q *txq, > > if (fep->quirks & FEC_QUIRK_SWAP_FRAME) > swap_buffer(bufaddr, hdr_len); > - > - dmabuf = dma_map_single(&fep->pdev->dev, bufaddr, > - hdr_len, DMA_TO_DEVICE); > - if (dma_mapping_error(&fep->pdev->dev, dmabuf)) { > - dev_kfree_skb_any(skb); > - if (net_ratelimit()) > - netdev_err(ndev, "Tx DMA memory map failed\n"); > - return NETDEV_TX_OK; > - } > } > > bdp->cbd_bufaddr = cpu_to_fec32(dmabuf); Hi Dheeraj, It seems to me that at this point of execution, without your patch, dmabuf can be one of two values: 1. txq->tso_hdrs_dma + index * TSO_HEADER_SIZE This is the default case. 2. txq->tx_bounce[index] This is the special case, which is handed in the conditional block that your patch updates. In case 1, I agree that tso_hdrs_dma is already mapped. But this case is not affected by your patch as the conditional block that includes dma_map_single() is not executed. In case 2, I do not see where txq->tx_bounce[index] is already mapped. Am I missing something?
diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c index 68725506a095..039de4c5044e 100644 --- a/drivers/net/ethernet/freescale/fec_main.c +++ b/drivers/net/ethernet/freescale/fec_main.c @@ -805,15 +805,6 @@ fec_enet_txq_put_hdr_tso(struct fec_enet_priv_tx_q *txq, if (fep->quirks & FEC_QUIRK_SWAP_FRAME) swap_buffer(bufaddr, hdr_len); - - dmabuf = dma_map_single(&fep->pdev->dev, bufaddr, - hdr_len, DMA_TO_DEVICE); - if (dma_mapping_error(&fep->pdev->dev, dmabuf)) { - dev_kfree_skb_any(skb); - if (net_ratelimit()) - netdev_err(ndev, "Tx DMA memory map failed\n"); - return NETDEV_TX_OK; - } } bdp->cbd_bufaddr = cpu_to_fec32(dmabuf);
The TSO header buffer is pre-allocated DMA memory, so there's no need to map it again with dma_map_single() in fec_enet_txq_put_hdr_tso(). Remove this redundant mapping operation. Fixes: 79f339125ea3 ("net: fec: Add software TSO support") Signed-off-by: Dheeraj Reddy Jonnalagadda <dheeraj.linuxdev@gmail.com> --- drivers/net/ethernet/freescale/fec_main.c | 9 --------- 1 file changed, 9 deletions(-)