Commit 481a8199 authored by Oliver Hartkopp's avatar Oliver Hartkopp Committed by David S. Miller

can: fix NOHZ local_softirq_pending 08 warning

When using nanosleep() in an userspace application we get a ratelimit warning

NOHZ: local_softirq_pending 08

for 10 times.

The echo of CAN frames is done from process context and softirq context only.
Therefore the usage of netif_rx() was wrong (for years).

This patch replaces netif_rx() with netif_rx_ni() which has to be used from
process/softirq context. It also adds a missing comment that can_send() must
no be used from hardirq context.
Signed-off-by: default avatarOliver Hartkopp <oliver@hartkopp.net>
Signed-off-by: default avatarUrs Thuermann <urs@isnogud.escape.de>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 0b6a05c1
...@@ -80,7 +80,7 @@ static void vcan_rx(struct sk_buff *skb, struct net_device *dev) ...@@ -80,7 +80,7 @@ static void vcan_rx(struct sk_buff *skb, struct net_device *dev)
skb->dev = dev; skb->dev = dev;
skb->ip_summed = CHECKSUM_UNNECESSARY; skb->ip_summed = CHECKSUM_UNNECESSARY;
netif_rx(skb); netif_rx_ni(skb);
} }
static netdev_tx_t vcan_tx(struct sk_buff *skb, struct net_device *dev) static netdev_tx_t vcan_tx(struct sk_buff *skb, struct net_device *dev)
......
...@@ -199,6 +199,8 @@ static int can_create(struct net *net, struct socket *sock, int protocol) ...@@ -199,6 +199,8 @@ static int can_create(struct net *net, struct socket *sock, int protocol)
* @skb: pointer to socket buffer with CAN frame in data section * @skb: pointer to socket buffer with CAN frame in data section
* @loop: loopback for listeners on local CAN sockets (recommended default!) * @loop: loopback for listeners on local CAN sockets (recommended default!)
* *
* Due to the loopback this routine must not be called from hardirq context.
*
* Return: * Return:
* 0 on success * 0 on success
* -ENETDOWN when the selected interface is down * -ENETDOWN when the selected interface is down
...@@ -278,7 +280,7 @@ int can_send(struct sk_buff *skb, int loop) ...@@ -278,7 +280,7 @@ int can_send(struct sk_buff *skb, int loop)
} }
if (newskb) if (newskb)
netif_rx(newskb); netif_rx_ni(newskb);
/* update statistics */ /* update statistics */
can_stats.tx_frames++; can_stats.tx_frames++;
......
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