From 8462fe3cd9ec8951871a20a4dfe36321ab075964 Mon Sep 17 00:00:00 2001 From: Daniel Drake Date: Mon, 1 May 2006 22:45:50 +0100 Subject: [PATCH] softmac: suggest per-frame-type TX rate This patch is the first step towards rate control inside softmac. The txrates substructure has been extended to provide different fields for different types of packets (management/data, unicast/multicast). These fields are updated on association to values compatible with the access point we are associating to. Drivers can then use the new ieee80211softmac_suggest_txrate() function call when deciding which rate to transmit each frame at. This is immensely useful for ZD1211, and bcm can use it too. The user can still specify a rate through iwconfig, which is matched for all transmissions (assuming the rate they have specified is in the rate set required by the AP). At a later date, we can incorporate automatic rate management into the ieee80211softmac_recalc_txrates() function. This patch also removes the mcast_fallback field. Sam Leffler pointed out that this field is meaningless, because no driver will ever be retransmitting mcast frames (they are not acked). Signed-off-by: Daniel Drake Acked-by: Johannes Berg Signed-off-by: John W. Linville --- net/ieee80211/softmac/ieee80211softmac_module.c | 117 +++++++++++++++++++----- 1 file changed, 96 insertions(+), 21 deletions(-) (limited to 'net/ieee80211/softmac/ieee80211softmac_module.c') diff --git a/net/ieee80211/softmac/ieee80211softmac_module.c b/net/ieee80211/softmac/ieee80211softmac_module.c index 6252be2c0db..4b2e57d1241 100644 --- a/net/ieee80211/softmac/ieee80211softmac_module.c +++ b/net/ieee80211/softmac/ieee80211softmac_module.c @@ -26,6 +26,7 @@ #include "ieee80211softmac_priv.h" #include +#include struct net_device *alloc_ieee80211softmac(int sizeof_priv) { @@ -61,14 +62,6 @@ struct net_device *alloc_ieee80211softmac(int sizeof_priv) softmac->wait_for_scan = ieee80211softmac_wait_for_scan_implementation; softmac->stop_scan = ieee80211softmac_stop_scan_implementation; - //TODO: The mcast rate has to be assigned dynamically somewhere (in scanning, association. Not sure...) - // It has to be set to the highest rate all stations in the current network can handle. - softmac->txrates.mcast_rate = IEEE80211_CCK_RATE_1MB; - softmac->txrates.mcast_fallback = IEEE80211_CCK_RATE_1MB; - /* This is reassigned in ieee80211softmac_start to sane values. */ - softmac->txrates.default_rate = IEEE80211_CCK_RATE_1MB; - softmac->txrates.default_fallback = IEEE80211_CCK_RATE_1MB; - /* to start with, we can't send anything ... */ netif_carrier_off(dev); @@ -170,15 +163,82 @@ static void ieee80211softmac_start_check_rates(struct ieee80211softmac_device *m } } -void ieee80211softmac_start(struct net_device *dev) +int ieee80211softmac_ratesinfo_rate_supported(struct ieee80211softmac_ratesinfo *ri, u8 rate) +{ + int search; + u8 search_rate; + + for (search = 0; search < ri->count; search++) { + search_rate = ri->rates[search]; + search_rate &= ~IEEE80211_BASIC_RATE_MASK; + if (rate == search_rate) + return 1; + } + + return 0; +} + +/* Finds the highest rate which is: + * 1. Present in ri (optionally a basic rate) + * 2. Supported by the device + * 3. Less than or equal to the user-defined rate + */ +static u8 highest_supported_rate(struct ieee80211softmac_device *mac, + struct ieee80211softmac_ratesinfo *ri, int basic_only) +{ + u8 user_rate = mac->txrates.user_rate; + int i; + + if (ri->count == 0) { + dprintk(KERN_ERR PFX "empty ratesinfo?\n"); + return IEEE80211_CCK_RATE_1MB; + } + + for (i = ri->count - 1; i >= 0; i--) { + u8 rate = ri->rates[i]; + if (basic_only && !(rate & IEEE80211_BASIC_RATE_MASK)) + continue; + rate &= ~IEEE80211_BASIC_RATE_MASK; + if (rate > user_rate) + continue; + if (ieee80211softmac_ratesinfo_rate_supported(&mac->ratesinfo, rate)) + return rate; + } + + /* If we haven't found a suitable rate by now, just trust the user */ + return user_rate; +} + +void ieee80211softmac_recalc_txrates(struct ieee80211softmac_device *mac) +{ + struct ieee80211softmac_txrates *txrates = &mac->txrates; + struct ieee80211softmac_txrates oldrates; + u32 change = 0; + + if (mac->txrates_change) + oldrates = mac->txrates; + + change |= IEEE80211SOFTMAC_TXRATECHG_DEFAULT; + txrates->default_rate = highest_supported_rate(mac, &mac->associnfo.supported_rates, 0); + + change |= IEEE80211SOFTMAC_TXRATECHG_DEFAULT_FBACK; + txrates->default_fallback = lower_rate(mac, txrates->default_rate); + + change |= IEEE80211SOFTMAC_TXRATECHG_MCAST; + txrates->mcast_rate = highest_supported_rate(mac, &mac->associnfo.supported_rates, 1); + + if (mac->txrates_change) + mac->txrates_change(mac->dev, change, &oldrates); + +} + +void ieee80211softmac_init_txrates(struct ieee80211softmac_device *mac) { - struct ieee80211softmac_device *mac = ieee80211_priv(dev); struct ieee80211_device *ieee = mac->ieee; u32 change = 0; + struct ieee80211softmac_txrates *txrates = &mac->txrates; struct ieee80211softmac_txrates oldrates; - ieee80211softmac_start_check_rates(mac); - /* TODO: We need some kind of state machine to lower the default rates * if we loose too many packets. */ @@ -193,22 +253,37 @@ void ieee80211softmac_start(struct net_device *dev) more reliable. Note similar logic in ieee80211softmac_wx_set_rate() */ if (ieee->modulation & IEEE80211_CCK_MODULATION) { - mac->txrates.default_rate = IEEE80211_CCK_RATE_11MB; - change |= IEEE80211SOFTMAC_TXRATECHG_DEFAULT; - mac->txrates.default_fallback = IEEE80211_CCK_RATE_5MB; - change |= IEEE80211SOFTMAC_TXRATECHG_DEFAULT_FBACK; + txrates->user_rate = IEEE80211_CCK_RATE_11MB; } else if (ieee->modulation & IEEE80211_OFDM_MODULATION) { - mac->txrates.default_rate = IEEE80211_OFDM_RATE_54MB; - change |= IEEE80211SOFTMAC_TXRATECHG_DEFAULT; - mac->txrates.default_fallback = IEEE80211_OFDM_RATE_24MB; - change |= IEEE80211SOFTMAC_TXRATECHG_DEFAULT_FBACK; + txrates->user_rate = IEEE80211_OFDM_RATE_54MB; } else assert(0); + + txrates->default_rate = IEEE80211_CCK_RATE_1MB; + change |= IEEE80211SOFTMAC_TXRATECHG_DEFAULT; + + txrates->default_fallback = IEEE80211_CCK_RATE_1MB; + change |= IEEE80211SOFTMAC_TXRATECHG_DEFAULT_FBACK; + + txrates->mcast_rate = IEEE80211_CCK_RATE_1MB; + change |= IEEE80211SOFTMAC_TXRATECHG_MCAST; + + txrates->mgt_mcast_rate = IEEE80211_CCK_RATE_1MB; + change |= IEEE80211SOFTMAC_TXRATECHG_MGT_MCAST; + if (mac->txrates_change) - mac->txrates_change(dev, change, &oldrates); + mac->txrates_change(mac->dev, change, &oldrates); mac->running = 1; } + +void ieee80211softmac_start(struct net_device *dev) +{ + struct ieee80211softmac_device *mac = ieee80211_priv(dev); + + ieee80211softmac_start_check_rates(mac); + ieee80211softmac_init_txrates(mac); +} EXPORT_SYMBOL_GPL(ieee80211softmac_start); void ieee80211softmac_stop(struct net_device *dev) -- cgit v1.2.3