@@ -5551,18 +5551,15 @@ static int stmmac_change_mtu(struct net_device *dev, int new_mtu)
{
struct stmmac_priv *priv = netdev_priv(dev);
int txfifosz = priv->plat->tx_fifo_size;
+ struct stmmac_dma_conf *dma_conf;
const int mtu = new_mtu;
+ int ret;
if (txfifosz == 0)
txfifosz = priv->dma_cap.tx_fifo_size;
txfifosz /= priv->plat->tx_queues_to_use;
- if (netif_running(dev)) {
- netdev_err(priv->dev, "must be stopped to change its MTU\n");
- return -EBUSY;
- }
-
if (stmmac_xdp_is_enabled(priv) && new_mtu > ETH_DATA_LEN) {
netdev_dbg(priv->dev, "Jumbo frames not supported for XDP\n");
return -EINVAL;
@@ -5574,8 +5571,29 @@ static int stmmac_change_mtu(struct net_device *dev, int new_mtu)
if ((txfifosz < new_mtu) || (new_mtu > BUF_SIZE_16KiB))
return -EINVAL;
- dev->mtu = mtu;
+ if (netif_running(dev)) {
+ netdev_dbg(priv->dev, "restarting interface to change its MTU\n");
+ /* Try to allocate the new DMA conf with the new mtu */
+ dma_conf = stmmac_setup_dma_desc(priv, mtu);
+ if (IS_ERR(dma_conf)) {
+ netdev_err(priv->dev, "failed allocating new dma conf for new MTU %d\n",
+ mtu);
+ return PTR_ERR(dma_conf);
+ }
+ stmmac_release(dev);
+
+ ret = __stmmac_open(dev, dma_conf);
+ kfree(dma_conf);
+ if (ret) {
+ netdev_err(priv->dev, "failed reopening the interface after MTU change\n");
+ return ret;
+ }
+
+ stmmac_set_rx_mode(dev);
+ }
+
+ dev->mtu = mtu;
netdev_update_features(dev);
return 0;
Remove the limitation where the interface needs to be down to change MTU by releasing and opening the stmmac driver to set the new MTU. Also call the set_filter function to correctly init the port. This permits to remove the EBUSY error while the ethernet port is running permitting a correct MTU change if for example a DSA request a MTU change for a switch CPU port. Signed-off-by: Christian Marangi <ansuelsmth@gmail.com> --- .../net/ethernet/stmicro/stmmac/stmmac_main.c | 30 +++++++++++++++---- 1 file changed, 24 insertions(+), 6 deletions(-)