Hello! On 02/12/2018 11:00 PM, Niklas Söderlund wrote: > Allow for chancing the MTU within the limit of the maximum size of a Changing. :-) > descriptor (2048 bytes). Add the callback to change MTU from user-space > and take the configurable MTU into account when configuring the > hardware. > > Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@xxxxxxxxxxxx> [...] > diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c > index c87f57ca44371586..a4870c9e42195802 100644 > --- a/drivers/net/ethernet/renesas/ravb_main.c > +++ b/drivers/net/ethernet/renesas/ravb_main.c > @@ -300,9 +300,9 @@ static void ravb_ring_format(struct net_device *ndev, int q) > for (i = 0; i < priv->num_rx_ring[q]; i++) { > /* RX descriptor */ > rx_desc = &priv->rx_ring[q][i]; > - rx_desc->ds_cc = cpu_to_le16(PKT_BUF_SZ); > + rx_desc->ds_cc = cpu_to_le16(priv->rx_buf_sz); > dma_addr = dma_map_single(ndev->dev.parent, priv->rx_skb[q][i]->data, > - PKT_BUF_SZ, > + le16_to_cpu(rx_desc->ds_cc), Why not 'priv->rx_buf_sz'? [...] > @@ -346,6 +346,10 @@ static int ravb_ring_init(struct net_device *ndev, int q) > int ring_size; > int i; > > + /* +16 gets room from the status from the card. */ > + priv->rx_buf_sz = (ndev->mtu <= 1492 ? PKT_BUF_SZ : ndev->mtu) + > + ETH_HLEN + VLAN_HLEN + ETH_FCS_LEN + 16; Mhm, I don't think FCS gets added to the frame buffer... And why add 16? [...] MBR, Sergei