iwlwifi: mvm: don't update quota in firmware too often

When updating quota in the firmware, it has to reset quite a bit
of internal state, which apparently can have an adverse impact on
its operation.

Avoid that by only updating the quota command when there are any
signification changes, i.e. added/removed bindings or changes in
quota that are bigger than 8 TU within a binding.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>

4 files changed, 33 insertions, 6 deletions

diff --git a/drivers/net/wireless/iwlwifi/mvm/constants.h b/drivers/net/wireless/iwlwifi/mvm/constants.h
index cb48656a8eaf..118108929a87 100644
--- a/drivers/net/wireless/iwlwifi/mvm/constants.h
+++ b/drivers/net/wireless/iwlwifi/mvm/constants.h
@@ -87,5 +87,6 @@
 #define IWL_MVM_BT_COEX_CORUNNING               1
 #define IWL_MVM_BT_COEX_MPLUT                   1
 #define IWL_MVM_FW_MCAST_FILTER_PASS_ALL        0
+#define IWL_MVM_QUOTA_THRESHOLD                 8
 
 #endif /* __MVM_CONSTANTS_H */
diff --git a/drivers/net/wireless/iwlwifi/mvm/fw.c b/drivers/net/wireless/iwlwifi/mvm/fw.c
index 21d606028ca6..23fd711a67e4 100644
--- a/drivers/net/wireless/iwlwifi/mvm/fw.c
+++ b/drivers/net/wireless/iwlwifi/mvm/fw.c
@@ -454,6 +454,9 @@ int iwl_mvm_up(struct iwl_mvm *mvm)
         for (i = 0; i < IWL_MVM_STATION_COUNT; i++)
                 RCU_INIT_POINTER(mvm->fw_id_to_mac_id[i], NULL);
 
+        /* reset quota debouncing buffer - 0xff will yield invalid data */
+        memset(&mvm->last_quota_cmd, 0xff, sizeof(mvm->last_quota_cmd));
+
         /* Add auxiliary station for scanning */
         ret = iwl_mvm_add_aux_sta(mvm);
         if (ret)
diff --git a/drivers/net/wireless/iwlwifi/mvm/mvm.h b/drivers/net/wireless/iwlwifi/mvm/mvm.h
index e292de96e09a..f05b7d7bcae3 100644
--- a/drivers/net/wireless/iwlwifi/mvm/mvm.h
+++ b/drivers/net/wireless/iwlwifi/mvm/mvm.h
@@ -709,6 +709,8 @@ struct iwl_mvm {
          */
         bool temperature_test;  /* Debug test temperature is enabled */
 
+        struct iwl_time_quota_cmd last_quota_cmd;
+
 #ifdef CONFIG_NL80211_TESTMODE
         u32 noa_duration;
         struct ieee80211_vif *noa_vif;
diff --git a/drivers/net/wireless/iwlwifi/mvm/quota.c b/drivers/net/wireless/iwlwifi/mvm/quota.c
index 5fd502db03d1..1eab2f2fee5d 100644
--- a/drivers/net/wireless/iwlwifi/mvm/quota.c
+++ b/drivers/net/wireless/iwlwifi/mvm/quota.c
@@ -175,12 +175,14 @@ int iwl_mvm_update_quotas(struct iwl_mvm *mvm,
                           struct ieee80211_vif *disabled_vif)
 {
         struct iwl_time_quota_cmd cmd = {};
-        int i, idx, ret, num_active_macs, quota, quota_rem, n_non_lowlat;
+        int i, idx, err, num_active_macs, quota, quota_rem, n_non_lowlat;
         struct iwl_mvm_quota_iterator_data data = {
                 .n_interfaces = {},
                 .colors = { -1, -1, -1, -1 },
                 .disabled_vif = disabled_vif,
         };
+        struct iwl_time_quota_cmd *last = &mvm->last_quota_cmd;
+        bool send = false;
 
         lockdep_assert_held(&mvm->mutex);
 
@@ -293,15 +295,34 @@ int iwl_mvm_update_quotas(struct iwl_mvm *mvm,
 
         /* check that we have non-zero quota for all valid bindings */
         for (i = 0; i < MAX_BINDINGS; i++) {
+                if (cmd.quotas[i].id_and_color != last->quotas[i].id_and_color)
+                        send = true;
+                if (cmd.quotas[i].max_duration != last->quotas[i].max_duration)
+                        send = true;
+                if (abs((int)le32_to_cpu(cmd.quotas[i].quota) -
+                        (int)le32_to_cpu(last->quotas[i].quota))
+                                                > IWL_MVM_QUOTA_THRESHOLD)
+                        send = true;
                 if (cmd.quotas[i].id_and_color == cpu_to_le32(FW_CTXT_INVALID))
                         continue;
                 WARN_ONCE(cmd.quotas[i].quota == 0,
                           "zero quota on binding %d\n", i);
         }
 
-        ret = iwl_mvm_send_cmd_pdu(mvm, TIME_QUOTA_CMD, 0,
-                                   sizeof(cmd), &cmd);
-        if (ret)
-                IWL_ERR(mvm, "Failed to send quota: %d\n", ret);
-        return ret;
+        if (send) {
+                err = iwl_mvm_send_cmd_pdu(mvm, TIME_QUOTA_CMD, 0,
+                                           sizeof(cmd), &cmd);
+        } else {
+                /* don't send a practically unchanged command, the firmware has
+                 * to re-initialize a lot of state and that can have an adverse
+                 * impact on it
+                 */
+                err = 0;
+        }
+
+        if (err)
+                IWL_ERR(mvm, "Failed to send quota: %d\n", err);
+        else
+                mvm->last_quota_cmd = cmd;
+        return err;
 }