| From 5c0ba62fd4b2dce08055a89600f1d834f9f0fe9e Mon Sep 17 00:00:00 2001 |
| From: Felix Fietkau <nbd@openwrt.org> |
| Date: Fri, 19 Feb 2010 01:46:36 +0100 |
| Subject: ath9k: fix rate control fallback rate selection |
| |
| From: Felix Fietkau <nbd@openwrt.org> |
| |
| commit 5c0ba62fd4b2dce08055a89600f1d834f9f0fe9e upstream. |
| |
| When selecting the tx fallback rate, rc.c used a separate variable |
| 'nrix' for storing the next rate index, however it did not use that as |
| reference for further rate index lowering. Because of that, it ended up |
| reusing the same rate for multiple multi-rate retry stages, thus |
| decreasing delivery probability under changing link conditions. |
| |
| This patch removes the separate (unnecessary) variable and fixes |
| fallback the way it was intended to work. |
| This should result in increased throughput and better link stability. |
| |
| Signed-off-by: Felix Fietkau <nbd@openwrt.org> |
| Signed-off-by: John W. Linville <linville@tuxdriver.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> |
| |
| --- |
| drivers/net/wireless/ath/ath9k/rc.c | 15 +++++++-------- |
| 1 file changed, 7 insertions(+), 8 deletions(-) |
| |
| --- a/drivers/net/wireless/ath/ath9k/rc.c |
| +++ b/drivers/net/wireless/ath/ath9k/rc.c |
| @@ -757,7 +757,7 @@ static void ath_get_rate(void *priv, str |
| struct ieee80211_tx_rate *rates = tx_info->control.rates; |
| struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data; |
| __le16 fc = hdr->frame_control; |
| - u8 try_per_rate, i = 0, rix, nrix; |
| + u8 try_per_rate, i = 0, rix; |
| int is_probe = 0; |
| |
| if (rate_control_send_low(sta, priv_sta, txrc)) |
| @@ -777,26 +777,25 @@ static void ath_get_rate(void *priv, str |
| |
| rate_table = sc->cur_rate_table; |
| rix = ath_rc_get_highest_rix(sc, ath_rc_priv, rate_table, &is_probe); |
| - nrix = rix; |
| |
| if (is_probe) { |
| /* set one try for probe rates. For the |
| * probes don't enable rts */ |
| ath_rc_rate_set_series(rate_table, &rates[i++], txrc, |
| - 1, nrix, 0); |
| + 1, rix, 0); |
| |
| /* Get the next tried/allowed rate. No RTS for the next series |
| * after the probe rate |
| */ |
| - ath_rc_get_lower_rix(rate_table, ath_rc_priv, rix, &nrix); |
| + ath_rc_get_lower_rix(rate_table, ath_rc_priv, rix, &rix); |
| ath_rc_rate_set_series(rate_table, &rates[i++], txrc, |
| - try_per_rate, nrix, 0); |
| + try_per_rate, rix, 0); |
| |
| tx_info->flags |= IEEE80211_TX_CTL_RATE_CTRL_PROBE; |
| } else { |
| /* Set the choosen rate. No RTS for first series entry. */ |
| ath_rc_rate_set_series(rate_table, &rates[i++], txrc, |
| - try_per_rate, nrix, 0); |
| + try_per_rate, rix, 0); |
| } |
| |
| /* Fill in the other rates for multirate retry */ |
| @@ -805,10 +804,10 @@ static void ath_get_rate(void *priv, str |
| if (i + 1 == 4) |
| try_per_rate = 4; |
| |
| - ath_rc_get_lower_rix(rate_table, ath_rc_priv, rix, &nrix); |
| + ath_rc_get_lower_rix(rate_table, ath_rc_priv, rix, &rix); |
| /* All other rates in the series have RTS enabled */ |
| ath_rc_rate_set_series(rate_table, &rates[i], txrc, |
| - try_per_rate, nrix, 1); |
| + try_per_rate, rix, 1); |
| } |
| |
| /* |
