The purpose of this was to keep all the queues updated with the Rx sequence numbers because unlikely yet possible situations where queues can't understand if a specific packet needs to be dropped or not.
Unfortunately, it was reported that this caused issues in our DMA engine. We don't fully understand how this is related, but this is being currently debugged. For now, just don't send this notification to the Rx queues. This de-facto reverts my commit 3c514bf831ac12356b695ff054bef641b9e99593:
iwlwifi: mvm: add a loose synchronization of the NSSN across Rx queues
Use the regular constant infra we have to make it easy to re-enable this mechanism when the firmware will be able to cope with the DMA stall.
This issue was reported here: https://bugzilla.kernel.org/show_bug.cgi?id=204873 https://bugzilla.kernel.org/show_bug.cgi?id=205001 and others maybe.
Fixes: 3c514bf831ac ("iwlwifi: mvm: add a loose synchronization of the NSSN across Rx queues") CC: stable@vger.kernel.org # 5.3+ Signed-off-by: Emmanuel Grumbach emmanuel.grumbach@intel.com --- v2: fix an unused variable warning v3: don't comment out the code --- .../wireless/intel/iwlwifi/mvm/constants.h | 1 + drivers/net/wireless/intel/iwlwifi/mvm/rxmq.c | 19 +++++++++++-------- 2 files changed, 12 insertions(+), 8 deletions(-)
diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/constants.h b/drivers/net/wireless/intel/iwlwifi/mvm/constants.h index 60aff2ecec12..58df25e2fb32 100644 --- a/drivers/net/wireless/intel/iwlwifi/mvm/constants.h +++ b/drivers/net/wireless/intel/iwlwifi/mvm/constants.h @@ -154,5 +154,6 @@ #define IWL_MVM_D3_DEBUG false #define IWL_MVM_USE_TWT false #define IWL_MVM_AMPDU_CONSEC_DROPS_DELBA 10 +#define IWL_MVM_USE_NSSN_SYNC 0
#endif /* __MVM_CONSTANTS_H */ diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/rxmq.c b/drivers/net/wireless/intel/iwlwifi/mvm/rxmq.c index 75a7af5ad7b2..27d15fa6fe04 100644 --- a/drivers/net/wireless/intel/iwlwifi/mvm/rxmq.c +++ b/drivers/net/wireless/intel/iwlwifi/mvm/rxmq.c @@ -514,14 +514,17 @@ static bool iwl_mvm_is_sn_less(u16 sn1, u16 sn2, u16 buffer_size)
static void iwl_mvm_sync_nssn(struct iwl_mvm *mvm, u8 baid, u16 nssn) { - struct iwl_mvm_rss_sync_notif notif = { - .metadata.type = IWL_MVM_RXQ_NSSN_SYNC, - .metadata.sync = 0, - .nssn_sync.baid = baid, - .nssn_sync.nssn = nssn, - }; - - iwl_mvm_sync_rx_queues_internal(mvm, (void *)¬if, sizeof(notif)); + if (IWL_MVM_USE_NSSN_SYNC) + { + struct iwl_mvm_rss_sync_notif notif = { + .metadata.type = IWL_MVM_RXQ_NSSN_SYNC, + .metadata.sync = 0, + .nssn_sync.baid = baid, + .nssn_sync.nssn = nssn, + }; + + iwl_mvm_sync_rx_queues_internal(mvm, (void *)¬if, sizeof(notif)); + } }
#define RX_REORDER_BUF_TIMEOUT_MQ (HZ / 10)