diff options
| author | Netanel Belgazal <netanel@amazon.com> | 2019-12-10 11:27:44 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-01-04 19:19:17 +0100 |
| commit | 252ac779a46de92f0e695267feca35443d566594 (patch) | |
| tree | 63def917ea675f706e369b67c465cebfaabace17 | |
| parent | 06067fd5a24b01957d5ca67192280f9e80b4bd6f (diff) | |
net: ena: fix napi handler misbehavior when the napi budget is zero
[ Upstream commit 24dee0c7478d1a1e00abdf5625b7f921467325dc ]
In netpoll the napi handler could be called with budget equal to zero.
Current ENA napi handler doesn't take that into consideration.
The napi handler handles Rx packets in a do-while loop.
Currently, the budget check happens only after decrementing the
budget, therefore the napi handler, in rare cases, could run over
MAX_INT packets.
In addition to that, this moves all budget related variables to int
calculation and stop mixing u32 to avoid ambiguity
Fixes: 1738cd3ed342 ("net: ena: Add a driver for Amazon Elastic Network Adapters (ENA)")
Signed-off-by: Netanel Belgazal <netanel@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/net/ethernet/amazon/ena/ena_netdev.c | 10 |
1 files changed, 7 insertions, 3 deletions
diff --git a/drivers/net/ethernet/amazon/ena/ena_netdev.c b/drivers/net/ethernet/amazon/ena/ena_netdev.c index c487d2a7d6dd..b4a145220aba 100644 --- a/drivers/net/ethernet/amazon/ena/ena_netdev.c +++ b/drivers/net/ethernet/amazon/ena/ena_netdev.c @@ -1238,8 +1238,8 @@ static int ena_io_poll(struct napi_struct *napi, int budget) struct ena_napi *ena_napi = container_of(napi, struct ena_napi, napi); struct ena_ring *tx_ring, *rx_ring; - u32 tx_work_done; - u32 rx_work_done; + int tx_work_done; + int rx_work_done = 0; int tx_budget; int napi_comp_call = 0; int ret; @@ -1256,7 +1256,11 @@ static int ena_io_poll(struct napi_struct *napi, int budget) } tx_work_done = ena_clean_tx_irq(tx_ring, tx_budget); - rx_work_done = ena_clean_rx_irq(rx_ring, napi, budget); + /* On netpoll the budget is zero and the handler should only clean the + * tx completions. + */ + if (likely(budget)) + rx_work_done = ena_clean_rx_irq(rx_ring, napi, budget); /* If the device is about to reset or down, avoid unmask * the interrupt and return 0 so NAPI won't reschedule |