From: Ilan Peer <ilan.peer@xxxxxxxxx>
The overcome instabilities in the RTT results add smoothing logic
to the reported results. In short, the smoothing logic tracks the
RTT average of each responder for a period of time, and in case
a new RTT results is found to be a spur, the tracked RTT average
is reported instead of the current RTT measurement.
Smooth logic debug configuration using iwl-dbg-cfg.ini:
- MVM_FTM_INITIATOR_ENABLE_SMOOTH: Set to 1 to enable smoothing logic
(default=0).
- MVM_FTM_INITIATOR_SMOOTH_ALPHA: A value between 0 - 100, defining
the weight of the current RTT results vs. the RTT average tracked
based on the previous results. A value of 100 means use only the
current RTT results.
- MVM_FTM_INITIATOR_SMOOTH_AGE_SEC: The maximal time in seconds in which
the RTT average tracked based on previous results is considered valid.
- MVM_FTM_INITIATOR_SMOOTH_UNDERSHOOT: if the current RTT is positive
and below the RTT average by at least this value, report the average
RTT instead of the current one. In units of picoseconds.
- MVM_FTM_INITIATOR_SMOOTH_OVERSHOOT: if the current RTT is positive
and above the RTT average by at least this value, report the average
RTT instead of the current one. In units of picoseconds.
Signed-off-by: Ilan Peer <ilan.peer@xxxxxxxxx>
Signed-off-by: Luca Coelho <luciano.coelho@xxxxxxxxx>
---
.../wireless/intel/iwlwifi/mvm/constants.h | 6 +
.../intel/iwlwifi/mvm/ftm-initiator.c | 123 ++++++++++++++++++
drivers/net/wireless/intel/iwlwifi/mvm/fw.c | 2 +
.../net/wireless/intel/iwlwifi/mvm/mac80211.c | 2 +
drivers/net/wireless/intel/iwlwifi/mvm/mvm.h | 5 +
5 files changed, 138 insertions(+)
diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/constants.h b/drivers/net/wireless/intel/iwlwifi/mvm/constants.h
index 426ca1f86500..2487871eac73 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/constants.h
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/constants.h
@@ -159,5 +159,11 @@
#define IWL_MVM_PHY_FILTER_CHAIN_B 0
#define IWL_MVM_PHY_FILTER_CHAIN_C 0
#define IWL_MVM_PHY_FILTER_CHAIN_D 0
+#define IWL_MVM_FTM_INITIATOR_ENABLE_SMOOTH false
+#define IWL_MVM_FTM_INITIATOR_SMOOTH_ALPHA 40
+/* 20016 pSec is 6 meter RTT, meaning 3 meter range */
+#define IWL_MVM_FTM_INITIATOR_SMOOTH_UNDERSHOOT 20016
+#define IWL_MVM_FTM_INITIATOR_SMOOTH_OVERSHOOT 20016
+#define IWL_MVM_FTM_INITIATOR_SMOOTH_AGE_SEC 2
#endif /* __MVM_CONSTANTS_H */
diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/ftm-initiator.c b/drivers/net/wireless/intel/iwlwifi/mvm/ftm-initiator.c
index 7efc6cb2d610..65dc443f37df 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/ftm-initiator.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/ftm-initiator.c
@@ -76,6 +76,13 @@ struct iwl_mvm_loc_entry {
u8 buf[];
};
+struct iwl_mvm_smooth_entry {
+ struct list_head list;
+ u8 addr[ETH_ALEN];
+ s64 rtt_avg;
+ u64 host_time;
+};
+
static void iwl_mvm_ftm_reset(struct iwl_mvm *mvm)
{
struct iwl_mvm_loc_entry *e, *t;
@@ -84,6 +91,7 @@ static void iwl_mvm_ftm_reset(struct iwl_mvm *mvm)
mvm->ftm_initiator.req_wdev = NULL;
memset(mvm->ftm_initiator.responses, 0,
sizeof(mvm->ftm_initiator.responses));
+
list_for_each_entry_safe(e, t, &mvm->ftm_initiator.loc_list, list) {
list_del(&e->list);
kfree(e);
@@ -120,6 +128,30 @@ void iwl_mvm_ftm_restart(struct iwl_mvm *mvm)
iwl_mvm_ftm_reset(mvm);
}
+void iwl_mvm_ftm_initiator_smooth_config(struct iwl_mvm *mvm)
+{
+ INIT_LIST_HEAD(&mvm->ftm_initiator.smooth.resp);
+
+ IWL_DEBUG_INFO(mvm,
+ "enable=%u, alpha=%u, age_jiffies=%u, thresh=(%u:%u)\n",
+ IWL_MVM_FTM_INITIATOR_ENABLE_SMOOTH,
+ IWL_MVM_FTM_INITIATOR_SMOOTH_ALPHA,
+ IWL_MVM_FTM_INITIATOR_SMOOTH_AGE_SEC * HZ,
+ IWL_MVM_FTM_INITIATOR_SMOOTH_OVERSHOOT,
+ IWL_MVM_FTM_INITIATOR_SMOOTH_UNDERSHOOT);
+}
+
+void iwl_mvm_ftm_initiator_smooth_stop(struct iwl_mvm *mvm)
+{
+ struct iwl_mvm_smooth_entry *se, *st;
+
+ list_for_each_entry_safe(se, st, &mvm->ftm_initiator.smooth.resp,
+ list) {
+ list_del(&se->list);
+ kfree(se);
+ }
+}
+
static int
iwl_ftm_range_request_status_to_err(enum iwl_tof_range_request_status s)
{
@@ -728,6 +760,95 @@ static int iwl_mvm_ftm_range_resp_valid(struct iwl_mvm *mvm, u8 request_id,
return 0;
}
+static void iwl_mvm_ftm_rtt_smoothing(struct iwl_mvm *mvm,
+ struct cfg80211_pmsr_result *res)
+{
+ struct iwl_mvm_smooth_entry *resp;
+ s64 rtt_avg, rtt = res->ftm.rtt_avg;
+ u32 undershoot, overshoot;
+ u8 alpha;
+ bool found;
+
+ if (!IWL_MVM_FTM_INITIATOR_ENABLE_SMOOTH)
+ return;
+
+ WARN_ON(rtt < 0);
+
+ if (res->status != NL80211_PMSR_STATUS_SUCCESS) {
+ IWL_DEBUG_INFO(mvm,
+ ": %pM: ignore failed measurement. Status=%u\n",
+ res->addr, res->status);
+ return;
+ }
+
+ found = false;
+ list_for_each_entry(resp, &mvm->ftm_initiator.smooth.resp, list) {
+ if (!memcmp(res->addr, resp->addr, ETH_ALEN)) {
+ found = true;
+ break;
+ }
+ }
+
+ if (!found) {
+ resp = kzalloc(sizeof(*resp), GFP_KERNEL);
+ if (!resp)
+ return;
+
+ memcpy(resp->addr, res->addr, ETH_ALEN);
+ list_add_tail(&resp->list, &mvm->ftm_initiator.smooth.resp);
+
+ resp->rtt_avg = rtt;
+
+ IWL_DEBUG_INFO(mvm, "new: %pM: rtt_avg=%lld\n",
+ resp->addr, resp->rtt_avg);
+ goto update_time;
+ }
+
+ if (res->host_time - resp->host_time >
+ IWL_MVM_FTM_INITIATOR_SMOOTH_AGE_SEC * 1000000000) {
+ resp->rtt_avg = rtt;
+
+ IWL_DEBUG_INFO(mvm, "expired: %pM: rtt_avg=%lld\n",
+ resp->addr, resp->rtt_avg);
+ goto update_time;
+ }
+
+ /* Smooth the results based on the tracked RTT average */
+ undershoot = IWL_MVM_FTM_INITIATOR_SMOOTH_UNDERSHOOT;
+ overshoot = IWL_MVM_FTM_INITIATOR_SMOOTH_OVERSHOOT;
+ alpha = IWL_MVM_FTM_INITIATOR_SMOOTH_ALPHA;
+
+ rtt_avg = (alpha * rtt + (100 - alpha) * resp->rtt_avg) / 100;
+
+ IWL_DEBUG_INFO(mvm,
+ "%pM: prev rtt_avg=%lld, new rtt_avg=%lld, rtt=%lld\n",
+ resp->addr, resp->rtt_avg, rtt_avg, rtt);
+
+ /*
+ * update the responder's average RTT results regardless of
+ * the under/over shoot logic below
+ */
+ resp->rtt_avg = rtt_avg;
+
+ /* smooth the results */
+ if (rtt_avg > rtt && (rtt_avg - rtt) > undershoot) {
+ res->ftm.rtt_avg = rtt_avg;
+
+ IWL_DEBUG_INFO(mvm,
+ "undershoot: val=%lld\n",
+ (rtt_avg - rtt));
+ } else if (rtt_avg < rtt && (rtt - rtt_avg) >
+ overshoot) {
+ res->ftm.rtt_avg = rtt_avg;
+ IWL_DEBUG_INFO(mvm,
+ "overshoot: val=%lld\n",
+ (rtt - rtt_avg));
+ }
+
+update_time:
+ resp->host_time = res->host_time;
+}
+
static void iwl_mvm_debug_range_resp(struct iwl_mvm *mvm, u8 index,
struct cfg80211_pmsr_result *res)
{
@@ -865,6 +986,8 @@ void iwl_mvm_ftm_range_resp(struct iwl_mvm *mvm, struct iwl_rx_cmd_buffer *rxb)
iwl_mvm_ftm_get_lci_civic(mvm, &result);
+ iwl_mvm_ftm_rtt_smoothing(mvm, &result);
+
cfg80211_pmsr_report(mvm->ftm_initiator.req_wdev,
mvm->ftm_initiator.req,
&result, GFP_KERNEL);
diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/fw.c b/drivers/net/wireless/intel/iwlwifi/mvm/fw.c
index 4d4315bc669e..897249201b06 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/fw.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/fw.c
@@ -1512,6 +1512,8 @@ int iwl_mvm_up(struct iwl_mvm *mvm)
iwl_mvm_tas_init(mvm);
iwl_mvm_leds_sync(mvm);
+ iwl_mvm_ftm_initiator_smooth_config(mvm);
+
IWL_DEBUG_INFO(mvm, "RT uCode started.\n");
return 0;
error:
diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c b/drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c
index 30e5a5b5664e..1c5f18d1b4c2 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c
@@ -1211,6 +1211,8 @@ void __iwl_mvm_mac_stop(struct iwl_mvm *mvm)
{
lockdep_assert_held(&mvm->mutex);
+ iwl_mvm_ftm_initiator_smooth_stop(mvm);
+
/* firmware counters are obviously reset now, but we shouldn't
* partially track so also clear the fw_reset_accu counters.
*/
diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/mvm.h b/drivers/net/wireless/intel/iwlwifi/mvm/mvm.h
index c57d45090715..ba1b74d10577 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/mvm.h
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/mvm.h
@@ -1107,6 +1107,9 @@ struct iwl_mvm {
struct wireless_dev *req_wdev;
struct list_head loc_list;
int responses[IWL_MVM_TOF_MAX_APS];
+ struct {
+ struct list_head resp;
+ } smooth;
} ftm_initiator;
struct list_head resp_pasn_list;
@@ -2011,6 +2014,8 @@ void iwl_mvm_ftm_lc_notif(struct iwl_mvm *mvm,
int iwl_mvm_ftm_start(struct iwl_mvm *mvm, struct ieee80211_vif *vif,
struct cfg80211_pmsr_request *request);
void iwl_mvm_ftm_abort(struct iwl_mvm *mvm, struct cfg80211_pmsr_request *req);
+void iwl_mvm_ftm_initiator_smooth_config(struct iwl_mvm *mvm);
+void iwl_mvm_ftm_initiator_smooth_stop(struct iwl_mvm *mvm);
/* TDLS */
--
2.28.0
