path: root/drivers/net
diff options
authorAlexander Lobakin <alobakin@dlink.ru>2019-11-27 12:41:23 +0300
committerDavid S. Miller <davem@davemloft.net>2019-11-27 11:22:51 -0800
commitb167191e2a851cb2e4c6ef8b91c83ff73ef41872 (patch)
treeda15f28da000517aa5c289b22315e85d0c68da53 /drivers/net
parentMerge branch 'mscc-skb-lists' (diff)
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')
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);