diff options
author | Raghu Vatsavayi <raghu.vatsavayi@cavium.com> | 2018-03-29 21:13:22 +0300 |
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committer | David S. Miller <davem@davemloft.net> | 2018-03-30 21:16:19 +0300 |
commit | ccdd0b4c35f2adb7434ed69a89bc68bb6e9089ea (patch) | |
tree | dc0a8e01b3a7cedf17724aff50ad049a220ee3af /drivers/net/ethernet/cavium/liquidio/lio_vf_main.c | |
parent | 6f14f49ce5eb00f533133df06c663fbaea13cd50 (diff) | |
download | linux-ccdd0b4c35f2adb7434ed69a89bc68bb6e9089ea.tar.xz |
liquidio: prevent rx queues from getting stalled
This commit has fix for RX traffic issues when we stress test the driver
with continuous ifconfig up/down under very high traffic conditions.
Reason for the issue is that, in existing liquidio_stop function NAPI is
disabled even before actual FW/HW interface is brought down via
send_rx_ctrl_cmd(lio, 0). Between time frame of NAPI disable and actual
interface down in firmware, firmware continuously enqueues rx traffic to
host. When interrupt happens for new packets, host irq handler fails in
scheduling NAPI as the NAPI is already disabled.
After "ifconfig <iface> up", Host re-enables NAPI but cannot schedule it
until it receives another Rx interrupt. Host never receives Rx interrupt as
it never cleared the Rx interrupt it received during interface down
operation. NIC Rx interrupt gets cleared only when Host processes queue and
clears the queue counts. Above anomaly leads to other issues like packet
overflow in FW/HW queues, backpressure.
Fix:
This commit fixes this issue by disabling NAPI only after informing
firmware to stop queueing packets to host via send_rx_ctrl_cmd(lio, 0).
send_rx_ctrl_cmd is not visible in the patch as it is already there in the
code. The DOWN command also waits for any pending packets to be processed
by NAPI so that the deadlock will not occur.
Signed-off-by: Raghu Vatsavayi <raghu.vatsavayi@cavium.com>
Acked-by: Derek Chickles <derek.chickles@cavium.com>
Signed-off-by: Felix Manlunas <felix.manlunas@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/ethernet/cavium/liquidio/lio_vf_main.c')
-rw-r--r-- | drivers/net/ethernet/cavium/liquidio/lio_vf_main.c | 23 |
1 files changed, 14 insertions, 9 deletions
diff --git a/drivers/net/ethernet/cavium/liquidio/lio_vf_main.c b/drivers/net/ethernet/cavium/liquidio/lio_vf_main.c index dc62698bdaf7..f92dfa411de6 100644 --- a/drivers/net/ethernet/cavium/liquidio/lio_vf_main.c +++ b/drivers/net/ethernet/cavium/liquidio/lio_vf_main.c @@ -1138,15 +1138,6 @@ static int liquidio_stop(struct net_device *netdev) /* tell Octeon to stop forwarding packets to host */ send_rx_ctrl_cmd(lio, 0); - if (oct->props[lio->ifidx].napi_enabled) { - list_for_each_entry_safe(napi, n, &netdev->napi_list, dev_list) - napi_disable(napi); - - oct->props[lio->ifidx].napi_enabled = 0; - - oct->droq[0]->ops.poll_mode = 0; - } - netif_info(lio, ifdown, lio->netdev, "Stopping interface!\n"); /* Inform that netif carrier is down */ lio->intf_open = 0; @@ -1159,6 +1150,20 @@ static int liquidio_stop(struct net_device *netdev) stop_txqs(netdev); + /* Wait for any pending Rx descriptors */ + if (lio_wait_for_clean_oq(oct)) + netif_info(lio, rx_err, lio->netdev, + "Proceeding with stop interface after partial RX desc processing\n"); + + if (oct->props[lio->ifidx].napi_enabled == 1) { + list_for_each_entry_safe(napi, n, &netdev->napi_list, dev_list) + napi_disable(napi); + + oct->props[lio->ifidx].napi_enabled = 0; + + oct->droq[0]->ops.poll_mode = 0; + } + dev_info(&oct->pci_dev->dev, "%s interface is stopped\n", netdev->name); return 0; |