[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 <dsd@gentoo.org>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/ieee80211/softmac/ieee80211softmac_module.c b/net/ieee80211/softmac/ieee80211softmac_module.c
index 6252be2..4b2e57d 100644
--- a/net/ieee80211/softmac/ieee80211softmac_module.c
+++ b/net/ieee80211/softmac/ieee80211softmac_module.c
@@ -26,6 +26,7 @@
#include "ieee80211softmac_priv.h"
#include <linux/sort.h>
+#include <linux/etherdevice.h>
struct net_device *alloc_ieee80211softmac(int sizeof_priv)
{
@@ -61,14 +62,6 @@
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 @@
}
}
-void ieee80211softmac_start(struct net_device *dev)
+int ieee80211softmac_ratesinfo_rate_supported(struct ieee80211softmac_ratesinfo *ri, u8 rate)
{
- struct ieee80211softmac_device *mac = ieee80211_priv(dev);
+ 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 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 @@
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)