From cb64edb6b89491edfdbae52ba7db9a8b8391d339 Mon Sep 17 00:00:00 2001 From: John Greene Date: Mon, 3 Dec 2012 06:19:33 +0000 Subject: [PATCH] 8139cp: properly support change of MTU values [v2] The 8139cp driver has a change_mtu function that has not been enabled since the dawn of the git repository. However, the generic eth_change_mtu is not used in its place, so that invalid MTU values can be set on the interface. Original patch salvages the broken code for the single case of setting the MTU while the interface is down, which is safe and also includes the range check. Now enhanced to support up or down interface. v2: fix case where rxbufsz isn't changed in the up state case Original patch from http://lkml.indiana.edu/hypermail/linux/kernel/1202.2/00770.html Testing: has been test on virtual 8139cp setup without issue, have no access real hardware 8139cp, need testing help. Signed-off-by: "John Greene" CC: "David S. Miller" Signed-off-by: David S. Miller --- drivers/net/ethernet/realtek/8139cp.c | 23 ++++------------------- 1 file changed, 4 insertions(+), 19 deletions(-) diff --git a/drivers/net/ethernet/realtek/8139cp.c b/drivers/net/ethernet/realtek/8139cp.c index 6cb96b4afdf5..0da3f5e9b1a5 100644 --- a/drivers/net/ethernet/realtek/8139cp.c +++ b/drivers/net/ethernet/realtek/8139cp.c @@ -1226,12 +1226,9 @@ static void cp_tx_timeout(struct net_device *dev) spin_unlock_irqrestore(&cp->lock, flags); } -#ifdef BROKEN static int cp_change_mtu(struct net_device *dev, int new_mtu) { struct cp_private *cp = netdev_priv(dev); - int rc; - unsigned long flags; /* check for invalid MTU, according to hardware limits */ if (new_mtu < CP_MIN_MTU || new_mtu > CP_MAX_MTU) @@ -1244,22 +1241,12 @@ static int cp_change_mtu(struct net_device *dev, int new_mtu) return 0; } - spin_lock_irqsave(&cp->lock, flags); - - cp_stop_hw(cp); /* stop h/w and free rings */ - cp_clean_rings(cp); - + /* network IS up, close it, reset MTU, and come up again. */ + cp_close(dev); dev->mtu = new_mtu; - cp_set_rxbufsize(cp); /* set new rx buf size */ - - rc = cp_init_rings(cp); /* realloc and restart h/w */ - cp_start_hw(cp); - - spin_unlock_irqrestore(&cp->lock, flags); - - return rc; + cp_set_rxbufsize(cp); + return cp_open(dev); } -#endif /* BROKEN */ static const char mii_2_8139_map[8] = { BasicModeCtrl, @@ -1835,9 +1822,7 @@ static const struct net_device_ops cp_netdev_ops = { .ndo_start_xmit = cp_start_xmit, .ndo_tx_timeout = cp_tx_timeout, .ndo_set_features = cp_set_features, -#ifdef BROKEN .ndo_change_mtu = cp_change_mtu, -#endif #ifdef CONFIG_NET_POLL_CONTROLLER .ndo_poll_controller = cp_poll_controller, -- 2.20.1