On embedded environments with hard memory limits it is a normal although
rare case when skb can't be allocated on rx part under high traffic.
In such OOM cases napi_complete_done() was not called.
So the napi object became in an invalid state like it is "scheduled".
Kernel do not re-schedules the poll of that napi object.
Consequently, kernel can not remove that object the system hangs on
`ifconfig down` waiting for a poll.
We are fixing this by gracefully closing napi poll routine with correct
invocation of napi_complete_done.
This was reproduced with artificially failing the allocation of skb to
simulate an "out of memory" error case and check that traffic does
not get stuck.
Fixes: 970a2e9864 ("net: ethernet: aquantia: Vector operations")
Signed-off-by: Igor Russkikh <igor.russkikh@aquantia.com>
Signed-off-by: Dmitry Bogdanov <dmitry.bogdanov@aquantia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
be6cef69ba