From: J.P. Tosoni <jp.tosoni@xxxxxxxxx>
In the rate control algorithms, the maximum retry count is limited by
a) a constant value obtained from the hardware driver
b) a constant limit (6ms) on the time allowed for all
retries of each frame.
Replace the retry count by existing configurable values from nl80211.
Use wiphy->retry_long for frames whose length exceed rts_threshold.
Use wiphy->retry_short for all other frames.
Check that the configured value does not exceed driver capabilities.
Use the new values as soon as the next frame is transmitted.
Caveat: the retry count for frames sent outside the context of a STA is
still taken from the hardware driver.
---
What I am seeking with this patch:
I believe the configuration of the retries will help making recovery
much faster when an AP (in infrastructure mode) or a peer (in mesh
mode) suddenly disappears.
>From Felix Fietkau's comments:
- short retries arbitrarily reserved for management frames: now it depends on
the use_rts flag which is set when frame length > rts_threshold, which matches
the standard.
- "minstrel_alloc ... never update (long_frame_max_tx_count) again"
The value is now directly used each time we send a frame, the configuration
should now apply immediately. (not yet tested, need to change iw)
net/mac80211/cfg.c | 6 ++++++
net/mac80211/rate.c | 31 ++++++++++++++++++++++++++++++-
2 files changed, 36 insertions(+), 1 deletions(-)
diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index 082f270..4f43beb 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -2203,11 +2203,17 @@ static int ieee80211_set_wiphy_params(struct wiphy *wiphy, u32 changed)
if (changed & WIPHY_PARAM_RETRY_SHORT) {
if (wiphy->retry_short > IEEE80211_MAX_TX_RETRY)
return -EINVAL;
+ if (wiphy->retry_short >
+ local->hw.max_rate_tries*local->hw.max_rates)
+ return -EINVAL;
local->hw.conf.short_frame_max_tx_count = wiphy->retry_short;
}
if (changed & WIPHY_PARAM_RETRY_LONG) {
if (wiphy->retry_long > IEEE80211_MAX_TX_RETRY)
return -EINVAL;
+ if (wiphy->retry_long >
+ local->hw.max_rate_tries*local->hw.max_rates)
+ return -EINVAL;
local->hw.conf.long_frame_max_tx_count = wiphy->retry_long;
}
if (changed &
diff --git a/net/mac80211/rate.c b/net/mac80211/rate.c
index a02bef3..a8eaca1 100644
--- a/net/mac80211/rate.c
+++ b/net/mac80211/rate.c
@@ -537,18 +537,42 @@ static void rate_control_fill_sta_table(struct ieee80211_sta *sta,
{
struct ieee80211_sta_rates *ratetbl = NULL;
int i;
+ int max_retries;
if (sta && !info->control.skip_table)
ratetbl = rcu_dereference(sta->rates);
+ if (sta) {
+ struct ieee80211_hw *hw;
+
+ hw = &container_of(sta, struct sta_info, sta)->local->hw;
+ if (info->control.use_rts)
+ max_retries = hw->conf.long_frame_max_tx_count;
+ else
+ max_retries = hw->conf.short_frame_max_tx_count;
+ } else {
+ /*
+ * No STA, we cannot access hw. Set to a max value, so that
+ * the values computed by the rate control algorithm will be
+ * used unlimited.
+ */
+ max_retries = max_rates * 256; /* garanteed max value of u8 */
+ }
+
/* Fill remaining rate slots with data from the sta rate table. */
max_rates = min_t(int, max_rates, IEEE80211_TX_RATE_TABLE_SIZE);
for (i = 0; i < max_rates; i++) {
- if (i < ARRAY_SIZE(info->control.rates) &&
+ if (max_retries <= 0) {
+ rates[i].idx = -1;
+ rates[i].count = 0;
+ } else if (i < ARRAY_SIZE(info->control.rates) &&
info->control.rates[i].idx >= 0 &&
info->control.rates[i].count) {
if (rates != info->control.rates)
rates[i] = info->control.rates[i];
+ if (max_retries < rates[i].count) {
+ rates[i].count = max_retries;
+ }
} else if (ratetbl) {
rates[i].idx = ratetbl->rate[i].idx;
rates[i].flags = ratetbl->rate[i].flags;
@@ -558,6 +582,9 @@ static void rate_control_fill_sta_table(struct ieee80211_sta *sta,
rates[i].count = ratetbl->rate[i].count_cts;
else
rates[i].count = ratetbl->rate[i].count;
+ if (max_retries < rates[i].count) {
+ rates[i].count = max_retries;
+ }
} else {
rates[i].idx = -1;
rates[i].count = 0;
@@ -565,6 +592,8 @@ static void rate_control_fill_sta_table(struct ieee80211_sta *sta,
if (rates[i].idx < 0 || !rates[i].count)
break;
+
+ max_retries -= rates[i].count;
}
}
--
1.7.2.5
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