iwlwifi: mvm: don't check system_pm_mode without mutex held

When we want to stop TX'ing because we are suspending, we
have two options: either we check system_pm_mode or we
check the mvm's status that has a bit for the suspend
flow.
The latter is better because test_bit is atomic. Also
add a call to synchronize_net after we set the bit to
make sure that all the new Tx see the bit before we
actually complete the suspend flow.

Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20210117130510.243c88781302.I5c0379c5a7e5d49410569e7fcd2fff7a419c6dea@changeid
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>

diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/d3.c b/drivers/net/wireless/intel/iwlwifi/mvm/d3.c
index 550755f..cc523fb 100644 (file)
--- a/drivers/net/wireless/intel/iwlwifi/mvm/d3.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/d3.c
@@ -997,6 +997,8 @@ static int __iwl_mvm_suspend(struct ieee80211_hw *hw,
 
        set_bit(IWL_MVM_STATUS_IN_D3, &mvm->status);
 
+       synchronize_net();
+
        vif = iwl_mvm_get_bss_vif(mvm);
        if (IS_ERR_OR_NULL(vif)) {
                ret = 1;

diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c b/drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c
index f2bb777..9477413 100644 (file)
--- a/drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c
@@ -816,8 +816,7 @@ void iwl_mvm_mac_itxq_xmit(struct ieee80211_hw *hw, struct ieee80211_txq *txq)
        rcu_read_lock();
        do {
                while (likely(!mvmtxq->stopped &&
-                             (mvm->trans->system_pm_mode ==
-                              IWL_PLAT_PM_MODE_DISABLED))) {
+                             !test_bit(IWL_MVM_STATUS_IN_D3, &mvm->status))) {
                        skb = ieee80211_tx_dequeue(hw, txq);
 
                        if (!skb) {