From f6346ad662e44d7086bc3c18fc19a33f0b95b576 Mon Sep 17 00:00:00 2001 From: Neil Horman Date: Tue, 21 Jul 2015 09:55:45 -0400 Subject: [PATCH] staging: unisys: Fix improper use of NETDEV_TX_BUSY Using NETDEV_TX_BUSY is tricky. Its meant for situations where the error in question is transient and quickly resolved. But the driver rarely is able to know that to a certainty. And in the case of visornic, it just uses it without any care for that, in the hopes that it won't loose frames, even if the problem is that the skb is somehow malformed for the hardware. If we get one of those kinds of skbs, NETDEV_TX_BUSY will just cause us to spin, processing the same error over and over. Fix it by dropping the frame, stopping the queue where appropriate, and returning NETDEV_TX_OK Signed-off-by: Neil Horman Signed-off-by: Benjamin Romer Signed-off-by: Greg Kroah-Hartman --- drivers/staging/unisys/visornic/visornic_main.c | 17 +++++++++++------ 1 file changed, 11 insertions(+), 6 deletions(-) diff --git a/drivers/staging/unisys/visornic/visornic_main.c b/drivers/staging/unisys/visornic/visornic_main.c index 338ca8c29915..8cc9017a67a1 100644 --- a/drivers/staging/unisys/visornic/visornic_main.c +++ b/drivers/staging/unisys/visornic/visornic_main.c @@ -787,7 +787,7 @@ visornic_close(struct net_device *netdev) * function is protected from concurrent calls by a spinlock xmit_lock * in the net_device struct, but as soon as the function returns it * can be called again. - * Returns NETDEV_TX_OK for success, NETDEV_TX_BUSY for error. + * Returns NETDEV_TX_OK. */ static int visornic_xmit(struct sk_buff *skb, struct net_device *netdev) @@ -806,7 +806,8 @@ visornic_xmit(struct sk_buff *skb, struct net_device *netdev) devdata->busy_cnt++; dev_dbg(&netdev->dev, "%s busy - queue stopped\n", __func__); - return NETDEV_TX_BUSY; + kfree_skb(skb); + return NETDEV_TX_OK; } /* sk_buff struct is used to host network data throughout all the @@ -827,7 +828,8 @@ visornic_xmit(struct sk_buff *skb, struct net_device *netdev) dev_err(&netdev->dev, "%s busy - first frag too small (%d)\n", __func__, firstfraglen); - return NETDEV_TX_BUSY; + kfree_skb(skb); + return NETDEV_TX_OK; } if ((len < ETH_MIN_PACKET_SIZE) && @@ -869,7 +871,8 @@ visornic_xmit(struct sk_buff *skb, struct net_device *netdev) dev_dbg(&netdev->dev, "%s busy - waiting for iovm to catch up\n", __func__); - return NETDEV_TX_BUSY; + kfree_skb(skb); + return NETDEV_TX_OK; } if (devdata->queuefullmsg_logged) devdata->queuefullmsg_logged = 0; @@ -911,7 +914,8 @@ visornic_xmit(struct sk_buff *skb, struct net_device *netdev) devdata->busy_cnt++; dev_err(&netdev->dev, "%s busy - copy frags failed\n", __func__); - return NETDEV_TX_BUSY; + kfree_skb(skb); + return NETDEV_TX_OK; } if (!visorchannel_signalinsert(devdata->dev->visorchannel, @@ -921,7 +925,8 @@ visornic_xmit(struct sk_buff *skb, struct net_device *netdev) devdata->busy_cnt++; dev_dbg(&netdev->dev, "%s busy - signalinsert failed\n", __func__); - return NETDEV_TX_BUSY; + kfree_skb(skb); + return NETDEV_TX_OK; } /* Track the skbs that have been sent to the IOVM for XMIT */ -- 2.11.0