iwl3945 : fix rate scaling (dd5b687e) · Commits · e / devices / android_kernel_xiaomi_markw

drivers/net/wireless/iwlwifi/iwl-3945-rs.c

+88 −39

Original line number	Diff line number	Diff line
		@@ -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))
		(high_tpt == IWL_INVALID_VALUE)) {

		if (high != IWL_RATE_INVALID && window->success_counter >= IWL_RATE_INCREASE_TH)
		scale_action = 1;
		else if ((low_tpt != IWL_INVALID_VALUE) &&
		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)
		/* 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;
		} 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;
		}
		}

		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;
		}