Hello!
On 2/16/2018 7:10 PM, Niklas Söderlund wrote:
Allow for changing the MTU within the limit of the maximum size of a
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>
---
drivers/net/ethernet/renesas/ravb.h | 1 +
drivers/net/ethernet/renesas/ravb_main.c | 34 +++++++++++++++++++++++++-------
2 files changed, 28 insertions(+), 7 deletions(-)
* Changes since v1
- Fix spelling error.
- s/le16_to_cpu(rx_desc->ds_cc)/priv->rx_buf_sz/.
- Drop ETH_FCS_LEN + 16 from rx_buf_sz calculation as pointed out by
Sergei.
diff --git a/drivers/net/ethernet/renesas/ravb.h b/drivers/net/ethernet/renesas/ravb.h
index 96a27b00c90e212a..b81f4faf7b10114d 100644
--- a/drivers/net/ethernet/renesas/ravb.h
+++ b/drivers/net/ethernet/renesas/ravb.h
@@ -1018,6 +1018,7 @@ struct ravb_private {
u32 dirty_rx[NUM_RX_QUEUE]; /* Producer ring indices */
u32 cur_tx[NUM_TX_QUEUE];
u32 dirty_tx[NUM_TX_QUEUE];
+ u32 rx_buf_sz; /* Based on MTU+slack. */
struct napi_struct napi[NUM_RX_QUEUE];
struct work_struct work;
/* MII transceiver section. */
diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c
index c87f57ca44371586..34e841306e04a3d3 100644
--- a/drivers/net/ethernet/renesas/ravb_main.c
+++ b/drivers/net/ethernet/renesas/ravb_main.c
@@ -238,7 +238,7 @@ static void ravb_ring_free(struct net_device *ndev, int q)
le32_to_cpu(desc->dptr)))
dma_unmap_single(ndev->dev.parent,
le32_to_cpu(desc->dptr),
- PKT_BUF_SZ,
+ priv->rx_buf_sz,
DMA_FROM_DEVICE);
}
ring_size = sizeof(struct ravb_ex_rx_desc) *
@@ -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,
+ priv->rx_buf_sz,
DMA_FROM_DEVICE);
/* We just set the data size to 0 for a failed mapping which
* should prevent DMA from happening...
@@ -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. */
You removed the addition of 16 but left the comment intact. :-)
Will have to fix it up in a follow-up patch now...
+ priv->rx_buf_sz = (ndev->mtu <= 1492 ? PKT_BUF_SZ : ndev->mtu) +
Not sure why PKT_BUF_SZ is 1538, sigh...
+ ETH_HLEN + VLAN_HLEN;
+
/* Allocate RX and TX skb rings */
priv->rx_skb[q] = kcalloc(priv->num_rx_ring[q],
sizeof(*priv->rx_skb[q]), GFP_KERNEL);
[...]
MBR, Sergei
