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| author |   Alexander Lobakin <alobakin@dlink.ru> | 2019-11-27 12:41:23 +0300 |
|---|---|---|
| committer |   David S. Miller <davem@davemloft.net> | 2019-11-27 11:22:51 -0800 |
| commit | b167191e2a851cb2e4c6ef8b91c83ff73ef41872 (patch) | |
| tree | da15f28da000517aa5c289b22315e85d0c68da53 /drivers/net | |
| parent | Merge branch 'mscc-skb-lists' (diff) | |
| download | linux-dev-b167191e2a851cb2e4c6ef8b91c83ff73ef41872.tar.xz linux-dev-b167191e2a851cb2e4c6ef8b91c83ff73ef41872.zip | |
net: wireless: intel: iwlwifi: fix GRO_NORMAL packet stalling
Commit 6570bc79c0df ("net: core: use listified Rx for GRO_NORMAL in
napi_gro_receive()") has applied batched GRO_NORMAL packets processing
to all napi_gro_receive() users, including mac80211-based drivers.
However, this change has led to a regression in iwlwifi driver [1][2] as
it is required for NAPI users to call napi_complete_done() or
napi_complete() and the end of every polling iteration, whilst iwlwifi
doesn't use NAPI scheduling at all and just calls napi_gro_flush().
In that particular case, packets which have not been already flushed
from napi->rx_list stall in it until at least next Rx cycle.
Fix this by adding a manual flushing of the list to iwlwifi driver right
before napi_gro_flush() call to mimic napi_complete() logics.
I prefer to open-code gro_normal_list() rather than exporting it for 2
reasons:
* to prevent from using it and napi_gro_flush() in any new drivers,
as it is the *really* bad way to use NAPI that should be avoided;
* to keep gro_normal_list() static and don't lose any CC optimizations.
I also don't add the "Fixes:" tag as the mentioned commit was only a
trigger that only exposed an improper usage of NAPI in this particular
driver.
[1] https://lore.kernel.org/netdev/PSXP216MB04388962C411CD0B17A86F47804A0@PSXP216MB0438.KORP216.PROD.OUTLOOK.COM
[2] https://bugzilla.kernel.org/show_bug.cgi?id=205647
Signed-off-by: Alexander Lobakin <alobakin@dlink.ru>
Acked-by: Luca Coelho <luciano.coelho@intel.com>
Reported-by: Nicholas Johnson <nicholas.johnson-opensource@outlook.com.au>
Tested-by: Nicholas Johnson <nicholas.johnson-opensource@outlook.com.au>
Reviewed-by: Edward Cree <ecree@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net')
| -rw-r--r-- | drivers/net/wireless/intel/iwlwifi/pcie/rx.c | 13 |
1 files changed, 11 insertions, 2 deletions
diff --git a/drivers/net/wireless/intel/iwlwifi/pcie/rx.c b/drivers/net/wireless/intel/iwlwifi/pcie/rx.c index a4d325fcf94a..452da44a21e0 100644 --- a/drivers/net/wireless/intel/iwlwifi/pcie/rx.c +++ b/drivers/net/wireless/intel/iwlwifi/pcie/rx.c @@ -1421,6 +1421,7 @@ out_err: static void iwl_pcie_rx_handle(struct iwl_trans *trans, int queue) { struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans); + struct napi_struct *napi; struct iwl_rxq *rxq; u32 r, i, count = 0; bool emergency = false; @@ -1526,8 +1527,16 @@ out: if (unlikely(emergency && count)) iwl_pcie_rxq_alloc_rbs(trans, GFP_ATOMIC, rxq); - if (rxq->napi.poll) - napi_gro_flush(&rxq->napi, false); + napi = &rxq->napi; + if (napi->poll) { + if (napi->rx_count) { + netif_receive_skb_list(&napi->rx_list); + INIT_LIST_HEAD(&napi->rx_list); + napi->rx_count = 0; + } + + napi_gro_flush(napi, false); + } iwl_pcie_rxq_restock(trans, rxq); } |