Commit be6cef69 authored Aug 30, 2019 by Dmitry Bogdanov Committed by David S. Miller Aug 31, 2019

net: aquantia: fix out of memory condition on rx side



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: 970a2e98 ("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>

parent 5c47e3ba

drivers/net/ethernet/aquantia/atlantic/aq_vec.c

+2 −1

Original line number	Original line	Diff line number	Diff line
	@@ -86,6 +86,7 @@ static int aq_vec_poll(struct napi_struct *napi, int budget)
	}		}
	}		}

			err_exit:
	if (!was_tx_cleaned)		if (!was_tx_cleaned)
	work_done = budget;		work_done = budget;

	@@ -95,7 +96,7 @@ static int aq_vec_poll(struct napi_struct *napi, int budget)
	1U << self->aq_ring_param.vec_idx);		1U << self->aq_ring_param.vec_idx);
	}		}
	}		}
	err_exit:
	return work_done;		return work_done;
	}		}