ath10k: disable wake_tx_queue for older devices

Ideally wake_tx_queue should be used regardless as
it is a requirement for reducing bufferbloat and
implementing airtime fairness in the future.

However some setups (typically low-end platforms
hosting QCA988X) suffer performance regressions
with the current wake_tx_queue implementation.
Therefore disable it unless it is really
beneficial with current codebase (which is when
firmware supports smart pull-push tx scheduling).

Signed-off-by: Michal Kazior <michal.kazior@tieto.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>

diff --git a/drivers/net/wireless/ath/ath10k/core.h b/drivers/net/wireless/ath/ath10k/core.h
index 9374bcd..30ae5bf 100644 (file)
--- a/drivers/net/wireless/ath/ath10k/core.h
+++ b/drivers/net/wireless/ath/ath10k/core.h
@@ -676,6 +676,7 @@ struct ath10k_fw_components {
 struct ath10k {
        struct ath_common ath_common;
        struct ieee80211_hw *hw;
+       struct ieee80211_ops *ops;
        struct device *dev;
        u8 mac_addr[ETH_ALEN];
 

diff --git a/drivers/net/wireless/ath/ath10k/mac.c b/drivers/net/wireless/ath/ath10k/mac.c
index 55c823f..fb8e38d 100644 (file)
--- a/drivers/net/wireless/ath/ath10k/mac.c
+++ b/drivers/net/wireless/ath/ath10k/mac.c
@@ -7506,21 +7506,32 @@ static const struct ieee80211_channel ath10k_5ghz_channels[] = {
 struct ath10k *ath10k_mac_create(size_t priv_size)
 {
        struct ieee80211_hw *hw;
+       struct ieee80211_ops *ops;
        struct ath10k *ar;
 
-       hw = ieee80211_alloc_hw(sizeof(struct ath10k) + priv_size, &ath10k_ops);
-       if (!hw)
+       ops = kmemdup(&ath10k_ops, sizeof(ath10k_ops), GFP_KERNEL);
+       if (!ops)
                return NULL;
 
+       hw = ieee80211_alloc_hw(sizeof(struct ath10k) + priv_size, ops);
+       if (!hw) {
+               kfree(ops);
+               return NULL;
+       }
+
        ar = hw->priv;
        ar->hw = hw;
+       ar->ops = ops;
 
        return ar;
 }
 
 void ath10k_mac_destroy(struct ath10k *ar)
 {
+       struct ieee80211_ops *ops = ar->ops;
+
        ieee80211_free_hw(ar->hw);
+       kfree(ops);
 }
 
 static const struct ieee80211_iface_limit ath10k_if_limits[] = {
@@ -7954,6 +7965,15 @@ int ath10k_mac_register(struct ath10k *ar)
                        ath10k_warn(ar, "failed to initialise DFS pattern detector\n");
        }
 
+       /* Current wake_tx_queue implementation imposes a significant
+        * performance penalty in some setups. The tx scheduling code needs
+        * more work anyway so disable the wake_tx_queue unless firmware
+        * supports the pull-push mechanism.
+        */
+       if (!test_bit(ATH10K_FW_FEATURE_PEER_FLOW_CONTROL,
+                     ar->running_fw->fw_file.fw_features))
+               ar->ops->wake_tx_queue = NULL;
+
        ret = ath_regd_init(&ar->ath_common.regulatory, ar->hw->wiphy,
                            ath10k_reg_notifier);
        if (ret) {