From: Emmanuel Grumbach emmanuel.grumbach@intel.com

When we act as an AP, new firmware versions handle internally the power saving clients and the driver doesn't know that the peers went to sleep. It is, hence, possible that a peer goes to sleep for a long time and stop pulling frames. This will cause its transmit queue to hang which is a condition that triggers the recovery flow in the driver.

While this client is certainly buggy (it should have pulled the frame based on the TIM IE in the beacon), we can't blow up because of a buggy client.

Change the current implementation to not enable the transmit queue hang detection on queues that serve peers when we act as an AP / GO.

We can still enable this mechanism using the debug configuration which can come in handy when we want to debug why the client doesn't wake up.

Cc: stable@vger.kernel.org # v4.13 Signed-off-by: Emmanuel Grumbach emmanuel.grumbach@intel.com Signed-off-by: Luca Coelho luciano.coelho@intel.com --- drivers/net/wireless/intel/iwlwifi/mvm/utils.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/utils.c b/drivers/net/wireless/intel/iwlwifi/mvm/utils.c index d46115e2d69e..19c1d1f76e15 100644 --- a/drivers/net/wireless/intel/iwlwifi/mvm/utils.c +++ b/drivers/net/wireless/intel/iwlwifi/mvm/utils.c @@ -1134,9 +1134,18 @@ unsigned int iwl_mvm_get_wd_timeout(struct iwl_mvm *mvm, unsigned int default_timeout = cmd_q ? IWL_DEF_WD_TIMEOUT : mvm->cfg->base_params->wd_timeout;

- if (!iwl_fw_dbg_trigger_enabled(mvm->fw, FW_DBG_TRIGGER_TXQ_TIMERS)) + if (!iwl_fw_dbg_trigger_enabled(mvm->fw, FW_DBG_TRIGGER_TXQ_TIMERS)) { + /* + * We can't know when the station is asleep or awake, so we + * must disable the queue hang detection. + */ + if (fw_has_capa(&mvm->fw->ucode_capa, + IWL_UCODE_TLV_CAPA_STA_PM_NOTIF) && + vif && vif->type == NL80211_IFTYPE_AP) + return IWL_WATCHDOG_DISABLED; return iwlmvm_mod_params.tfd_q_hang_detect ? default_timeout : IWL_WATCHDOG_DISABLED; + }

trigger = iwl_fw_dbg_get_trigger(mvm->fw, FW_DBG_TRIGGER_TXQ_TIMERS); txq_timer = (void *)trigger->data;