From a5898ea09aaded8a8236b12f3920f4e6f9b8fc13 Mon Sep 17 00:00:00 2001 From: Harini Katakam Date: Wed, 6 May 2015 22:27:18 +0530 Subject: [PATCH] net: macb: Add change_mtu callback with jumbo support Add macb_change_mtu callback; if jumbo frame support is present allow mtu size changes upto (jumbo max length allowed - headers). Signed-off-by: Harini Katakam Reviewed-by: Punnaiah Choudary Kalluri Signed-off-by: David S. Miller --- drivers/net/ethernet/cadence/macb.c | 24 +++++++++++++++++++++++- 1 file changed, 23 insertions(+), 1 deletion(-) diff --git a/drivers/net/ethernet/cadence/macb.c b/drivers/net/ethernet/cadence/macb.c index cb84587d7555..97c664611e84 100644 --- a/drivers/net/ethernet/cadence/macb.c +++ b/drivers/net/ethernet/cadence/macb.c @@ -54,6 +54,8 @@ #define MACB_MAX_TX_LEN ((unsigned int)((1 << MACB_TX_FRMLEN_SIZE) - 1)) #define GEM_MAX_TX_LEN ((unsigned int)((1 << GEM_TX_FRMLEN_SIZE) - 1)) +#define GEM_MTU_MIN_SIZE 68 + /* * Graceful stop timeouts in us. We should allow up to * 1 frame time (10 Mbits/s, full-duplex, ignoring collisions) @@ -1855,6 +1857,26 @@ static int macb_close(struct net_device *dev) return 0; } +static int macb_change_mtu(struct net_device *dev, int new_mtu) +{ + struct macb *bp = netdev_priv(dev); + u32 max_mtu; + + if (netif_running(dev)) + return -EBUSY; + + max_mtu = ETH_DATA_LEN; + if (bp->caps | MACB_CAPS_JUMBO) + max_mtu = gem_readl(bp, JML) - ETH_HLEN - ETH_FCS_LEN; + + if ((new_mtu > max_mtu) || (new_mtu < GEM_MTU_MIN_SIZE)) + return -EINVAL; + + dev->mtu = new_mtu; + + return 0; +} + static void gem_update_stats(struct macb *bp) { int i; @@ -2131,7 +2153,7 @@ static const struct net_device_ops macb_netdev_ops = { .ndo_get_stats = macb_get_stats, .ndo_do_ioctl = macb_ioctl, .ndo_validate_addr = eth_validate_addr, - .ndo_change_mtu = eth_change_mtu, + .ndo_change_mtu = macb_change_mtu, .ndo_set_mac_address = eth_mac_addr, #ifdef CONFIG_NET_POLL_CONTROLLER .ndo_poll_controller = macb_poll_controller, -- 2.20.1