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Diffstat (limited to 'drivers/net/wireless/iwlwifi/iwl-3945-rs.c')
-rw-r--r--drivers/net/wireless/iwlwifi/iwl-3945-rs.c127
1 files changed, 88 insertions, 39 deletions
diff --git a/drivers/net/wireless/iwlwifi/iwl-3945-rs.c b/drivers/net/wireless/iwlwifi/iwl-3945-rs.c
index a2664589c88..f65c308a671 100644
--- a/drivers/net/wireless/iwlwifi/iwl-3945-rs.c
+++ b/drivers/net/wireless/iwlwifi/iwl-3945-rs.c
@@ -127,6 +127,7 @@ static struct iwl3945_tpt_entry iwl3945_tpt_table_g[] = {
#define IWL_RATE_MIN_FAILURE_TH 8
#define IWL_RATE_MIN_SUCCESS_TH 8
#define IWL_RATE_DECREASE_TH 1920
+#define IWL_RATE_RETRY_TH 15
static u8 iwl3945_get_rate_index_by_rssi(s32 rssi, enum ieee80211_band band)
{
@@ -298,37 +299,53 @@ static void iwl3945_collect_tx_data(struct iwl3945_rs_sta *rs_sta,
}
spin_lock_irqsave(&rs_sta->lock, flags);
- while (retries--) {
- /* If we have filled up the window then subtract one from the
- * success counter if the high-bit is counting toward
- * success */
- if (window->counter == IWL_RATE_MAX_WINDOW) {
- if (window->data & (1ULL << (IWL_RATE_MAX_WINDOW - 1)))
+ /*
+ * Keep track of only the latest 62 tx frame attempts in this rate's
+ * history window; anything older isn't really relevant any more.
+ * If we have filled up the sliding window, drop the oldest attempt;
+ * if the oldest attempt (highest bit in bitmap) shows "success",
+ * subtract "1" from the success counter (this is the main reason
+ * we keep these bitmaps!).
+ * */
+ while (retries > 0) {
+ if (window->counter >= IWL_RATE_MAX_WINDOW) {
+
+ /* remove earliest */
+ window->counter = IWL_RATE_MAX_WINDOW - 1;
+
+ if (window->data & (1ULL << (IWL_RATE_MAX_WINDOW - 1))) {
+ window->data &= ~(1ULL << (IWL_RATE_MAX_WINDOW - 1));
window->success_counter--;
- } else
- window->counter++;
+ }
+ }
- /* Slide the window to the left one bit */
- window->data = (window->data << 1);
+ /* Increment frames-attempted counter */
+ window->counter++;
- /* If this packet was a success then set the low bit high */
- if (success) {
+ /* Shift bitmap by one frame (throw away oldest history),
+ * OR in "1", and increment "success" if this
+ * frame was successful. */
+ window->data <<= 1;
+ if (success > 0) {
window->success_counter++;
- window->data |= 1;
+ window->data |= 0x1;
+ success--;
}
- /* window->counter can't be 0 -- it is either >0 or
- * IWL_RATE_MAX_WINDOW */
- window->success_ratio = 12800 * window->success_counter /
- window->counter;
-
- /* Tag this window as having been updated */
- window->stamp = jiffies;
-
+ retries--;
}
+ /* Calculate current success ratio, avoid divide-by-0! */
+ if (window->counter > 0)
+ window->success_ratio = 128 * (100 * window->success_counter)
+ / window->counter;
+ else
+ window->success_ratio = IWL_INVALID_VALUE;
+
fail_count = window->counter - window->success_counter;
+
+ /* Calculate average throughput, if we have enough history. */
if ((fail_count >= IWL_RATE_MIN_FAILURE_TH) ||
(window->success_counter >= IWL_RATE_MIN_SUCCESS_TH))
window->average_tpt = ((window->success_ratio *
@@ -336,6 +353,9 @@ static void iwl3945_collect_tx_data(struct iwl3945_rs_sta *rs_sta,
else
window->average_tpt = IWL_INVALID_VALUE;
+ /* Tag this window as having been updated */
+ window->stamp = jiffies;
+
spin_unlock_irqrestore(&rs_sta->lock, flags);
}
@@ -468,7 +488,10 @@ static void rs_tx_status(void *priv_rate, struct ieee80211_supported_band *sband
IWL_DEBUG_RATE(priv, "enter\n");
- retries = info->status.rates[0].count;
+ retries = info->status.rates[0].count - 1;
+ /* Sanity Check for retries */
+ if (retries > IWL_RATE_RETRY_TH)
+ retries = IWL_RATE_RETRY_TH;
first_index = sband->bitrates[info->status.rates[0].idx].hw_value;
if ((first_index < 0) || (first_index >= IWL_RATE_COUNT_3945)) {
@@ -724,7 +747,7 @@ static void rs_get_rate(void *priv_r, struct ieee80211_sta *sta,
fail_count = window->counter - window->success_counter;
- if (((fail_count <= IWL_RATE_MIN_FAILURE_TH) &&
+ if (((fail_count < IWL_RATE_MIN_FAILURE_TH) &&
(window->success_counter < IWL_RATE_MIN_SUCCESS_TH))) {
spin_unlock_irqrestore(&rs_sta->lock, flags);
@@ -735,6 +758,9 @@ static void rs_get_rate(void *priv_r, struct ieee80211_sta *sta,
window->counter,
window->success_counter,
rs_sta->expected_tpt ? "not " : "");
+
+ /* Can't calculate this yet; not enough history */
+ window->average_tpt = IWL_INVALID_VALUE;
goto out;
}
@@ -750,6 +776,7 @@ static void rs_get_rate(void *priv_r, struct ieee80211_sta *sta,
if ((max_rate_idx != -1) && (max_rate_idx < high))
high = IWL_RATE_INVALID;
+ /* Collect Measured throughputs of adjacent rates */
if (low != IWL_RATE_INVALID)
low_tpt = rs_sta->win[low].average_tpt;
@@ -758,24 +785,43 @@ static void rs_get_rate(void *priv_r, struct ieee80211_sta *sta,
spin_unlock_irqrestore(&rs_sta->lock, flags);
- scale_action = 1;
+ scale_action = 0;
+ /* Low success ratio , need to drop the rate */
if ((window->success_ratio < IWL_RATE_DECREASE_TH) || !current_tpt) {
IWL_DEBUG_RATE(priv, "decrease rate because of low success_ratio\n");
scale_action = -1;
+
+ /* No throughput measured yet for adjacent rates,
+ * try increase */
} else if ((low_tpt == IWL_INVALID_VALUE) &&
- (high_tpt == IWL_INVALID_VALUE))
- scale_action = 1;
- else if ((low_tpt != IWL_INVALID_VALUE) &&
+ (high_tpt == IWL_INVALID_VALUE)) {
+
+ if (high != IWL_RATE_INVALID && window->success_counter >= IWL_RATE_INCREASE_TH)
+ scale_action = 1;
+ else if (low != IWL_RATE_INVALID)
+ scale_action = -1;
+
+ /* Both adjacent throughputs are measured, but neither one has
+ * better throughput; we're using the best rate, don't change
+ * it! */
+ } else if ((low_tpt != IWL_INVALID_VALUE) &&
(high_tpt != IWL_INVALID_VALUE) &&
(low_tpt < current_tpt) && (high_tpt < current_tpt)) {
+
IWL_DEBUG_RATE(priv, "No action -- low [%d] & high [%d] < "
"current_tpt [%d]\n",
low_tpt, high_tpt, current_tpt);
scale_action = 0;
+
+ /* At least one of the rates has better throughput */
} else {
if (high_tpt != IWL_INVALID_VALUE) {
- if (high_tpt > current_tpt)
+
+ /* High rate has better throughput, Increase
+ * rate */
+ if (high_tpt > current_tpt &&
+ window->success_ratio >= IWL_RATE_INCREASE_TH)
scale_action = 1;
else {
IWL_DEBUG_RATE(priv,
@@ -787,29 +833,31 @@ static void rs_get_rate(void *priv_r, struct ieee80211_sta *sta,
IWL_DEBUG_RATE(priv,
"decrease rate because of low tpt\n");
scale_action = -1;
- } else
+ } else if (window->success_counter >= IWL_RATE_INCREASE_TH) {
+ /* Lower rate has better
+ * throughput,decrease rate */
scale_action = 1;
+ }
}
}
- if (scale_action == -1) {
- if (window->success_ratio > IWL_SUCCESS_DOWN_TH)
- scale_action = 0;
- } else if (scale_action == 1) {
- if (window->success_ratio < IWL_SUCCESS_UP_TH) {
- IWL_DEBUG_RATE(priv, "No action -- success_ratio [%d] < "
- "SUCCESS UP\n", window->success_ratio);
- scale_action = 0;
- }
- }
+ /* Sanity check; asked for decrease, but success rate or throughput
+ * has been good at old rate. Don't change it. */
+ if ((scale_action == -1) && (low != IWL_RATE_INVALID) &&
+ ((window->success_ratio > IWL_RATE_HIGH_TH) ||
+ (current_tpt > (100 * rs_sta->expected_tpt[low]))))
+ scale_action = 0;
switch (scale_action) {
case -1:
+
+ /* Decrese rate */
if (low != IWL_RATE_INVALID)
index = low;
break;
case 1:
+ /* Increase rate */
if (high != IWL_RATE_INVALID)
index = high;
@@ -817,6 +865,7 @@ static void rs_get_rate(void *priv_r, struct ieee80211_sta *sta,
case 0:
default:
+ /* No change */
break;
}
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2024-12-22 11:59:30 +0000