4.4-stable review patch. If anyone has any objections, please let me know.
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[ Upstream commit 426a593e641ebf0d9288f0a2fcab644a86820220 ]
In the original ftmac100_interrupt(), the interrupts are only disabled when the condition "netif_running(netdev)" is true. However, this condition causes kerenl hang in the following case. When the user requests to disable the network device, kernel will clear the bit __LINK_STATE_START from the dev->state and then call the driver's ndo_stop function. Network device interrupts are not blocked during this process. If an interrupt occurs between clearing __LINK_STATE_START and stopping network device, kernel cannot disable the interrupts due to the condition "netif_running(netdev)" in the ISR. Hence, kernel will hang due to the continuous interruption of the network device.
In order to solve the above problem, the interrupts of the network device should always be disabled in the ISR without being restricted by the condition "netif_running(netdev)".
[V2] Remove unnecessary curly braces.
Signed-off-by: Vincent Chen vincentc@andestech.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/ethernet/faraday/ftmac100.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-)
diff --git a/drivers/net/ethernet/faraday/ftmac100.c b/drivers/net/ethernet/faraday/ftmac100.c index dce5f7b7f772..05e1f923f49e 100644 --- a/drivers/net/ethernet/faraday/ftmac100.c +++ b/drivers/net/ethernet/faraday/ftmac100.c @@ -865,11 +865,10 @@ static irqreturn_t ftmac100_interrupt(int irq, void *dev_id) struct net_device *netdev = dev_id; struct ftmac100 *priv = netdev_priv(netdev);
- if (likely(netif_running(netdev))) { - /* Disable interrupts for polling */ - ftmac100_disable_all_int(priv); + /* Disable interrupts for polling */ + ftmac100_disable_all_int(priv); + if (likely(netif_running(netdev))) napi_schedule(&priv->napi); - }
return IRQ_HANDLED; }