Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 8462fe3c authored by Daniel Drake's avatar Daniel Drake Committed by John W. Linville
Browse files

[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: default avatarDaniel Drake <dsd@gentoo.org>
Acked-by: default avatarJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: default avatarJohn W. Linville <linville@tuxdriver.com>
parent 461c078c

include/net/ieee80211softmac.h

+33 −5
Original line number Diff line number Diff line
@@ -87,6 +87,9 @@ struct ieee80211softmac_assoc_info { 
	/* BSSID we're trying to associate to */

	char bssid[ETH_ALEN];



	/* Rates supported by the network */

	struct ieee80211softmac_ratesinfo supported_rates;

	

	/* some flags.

	 * static_essid is valid if the essid is constant,

	 * this is for use by the wx handlers only.
@@ -132,23 +135,26 @@ enum { 
struct ieee80211softmac_txrates {

	/* The Bit-Rate to be used for multicast frames. */

	u8 mcast_rate;

	/* The Bit-Rate to be used for multicast fallback

	 * (If the device supports fallback and hardware-retry)

	 */

	u8 mcast_fallback;



	/* The Bit-Rate to be used for multicast management frames. */

	u8 mgt_mcast_rate;



	/* The Bit-Rate to be used for any other (normal) data packet. */

	u8 default_rate;

	/* The Bit-Rate to be used for default fallback

	 * (If the device supports fallback and hardware-retry)

	 */

	u8 default_fallback;



	/* This is the rate that the user asked for */

	u8 user_rate;

};



/* Bits for txrates_change callback. */

#define IEEE80211SOFTMAC_TXRATECHG_DEFAULT		(1 << 0) /* default_rate */

#define IEEE80211SOFTMAC_TXRATECHG_DEFAULT_FBACK	(1 << 1) /* default_fallback */

#define IEEE80211SOFTMAC_TXRATECHG_MCAST		(1 << 2) /* mcast_rate */

#define IEEE80211SOFTMAC_TXRATECHG_MCAST_FBACK		(1 << 3) /* mcast_fallback */

#define IEEE80211SOFTMAC_TXRATECHG_MGT_MCAST		(1 << 3) /* mgt_mcast_rate */



struct ieee80211softmac_device {

	/* 802.11 structure for data stuff */
@@ -250,6 +256,28 @@ extern void ieee80211softmac_fragment_lost(struct net_device *dev, 
 * Note that the rates need to be sorted. */

extern void ieee80211softmac_set_rates(struct net_device *dev, u8 count, u8 *rates);



/* Helper function which advises you the rate at which a frame should be

 * transmitted at. */

static inline u8 ieee80211softmac_suggest_txrate(struct ieee80211softmac_device *mac,

						 int is_multicast,

						 int is_mgt)

{

	struct ieee80211softmac_txrates *txrates = &mac->txrates;



	if (!mac->associated)

		return txrates->mgt_mcast_rate;



	/* We are associated, sending unicast frame */

	if (!is_multicast)

		return txrates->default_rate;



	/* We are associated, sending multicast frame */

	if (is_mgt)

		return txrates->mgt_mcast_rate;

	else

		return txrates->mcast_rate;

}



/* Start the SoftMAC. Call this after you initialized the device

 * and it is ready to run.

 */

net/ieee80211/softmac/ieee80211softmac_assoc.c

+7 −12
Original line number Diff line number Diff line
@@ -96,6 +96,7 @@ ieee80211softmac_disassoc(struct ieee80211softmac_device *mac) 
	mac->associated = 0;

	mac->associnfo.bssvalid = 0;

	mac->associnfo.associating = 0;

	ieee80211softmac_init_txrates(mac);

	ieee80211softmac_call_events_locked(mac, IEEE80211SOFTMAC_EVENT_DISASSOCIATED, NULL);

	spin_unlock_irqrestore(&mac->lock, flags);

}
@@ -118,24 +119,15 @@ ieee80211softmac_send_disassoc_req(struct ieee80211softmac_device *mac, u16 reas 
static inline int

we_support_all_basic_rates(struct ieee80211softmac_device *mac, u8 *from, u8 from_len)

{

	int idx, search, found;

	u8 rate, search_rate;

	int idx;

	u8 rate;



	for (idx = 0; idx < (from_len); idx++) {

		rate = (from)[idx];

		if (!(rate & IEEE80211_BASIC_RATE_MASK))

			continue;

		found = 0;

		rate &= ~IEEE80211_BASIC_RATE_MASK;

		for (search = 0; search < mac->ratesinfo.count; search++) {

			search_rate = mac->ratesinfo.rates[search];

			search_rate &= ~IEEE80211_BASIC_RATE_MASK;

			if (rate == search_rate) {

				found = 1;

				break;

			}

		}

		if (!found)

		if (!ieee80211softmac_ratesinfo_rate_supported(&mac->ratesinfo, rate))

			return 0;

	}

	return 1;
@@ -310,6 +302,9 @@ ieee80211softmac_associated(struct ieee80211softmac_device *mac, 
	struct ieee80211softmac_network *net)

{

	mac->associnfo.associating = 0;

	mac->associnfo.supported_rates = net->supported_rates;

	ieee80211softmac_recalc_txrates(mac);



	mac->associated = 1;

	if (mac->set_bssid_filter)

		mac->set_bssid_filter(mac->dev, net->bssid);

net/ieee80211/softmac/ieee80211softmac_module.c

+96 −21
Original line number Diff line number Diff line
@@ -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 @@ 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)

net/ieee80211/softmac/ieee80211softmac_priv.h

+3 −0
Original line number Diff line number Diff line
@@ -116,7 +116,10 @@ ieee80211softmac_get_network_by_essid(struct ieee80211softmac_device *mac, 
	struct ieee80211softmac_essid *essid);



/* Rates related */

int ieee80211softmac_ratesinfo_rate_supported(struct ieee80211softmac_ratesinfo *ri, u8 rate);

u8 ieee80211softmac_lower_rate_delta(struct ieee80211softmac_device *mac, u8 rate, int delta);

void ieee80211softmac_init_txrates(struct ieee80211softmac_device *mac);

void ieee80211softmac_recalc_txrates(struct ieee80211softmac_device *mac);

static inline u8 lower_rate(struct ieee80211softmac_device *mac, u8 rate) {

	return ieee80211softmac_lower_rate_delta(mac, rate, 1);

}

net/ieee80211/softmac/ieee80211softmac_wx.c

+2 −2
Original line number Diff line number Diff line
@@ -211,8 +211,8 @@ ieee80211softmac_wx_set_rate(struct net_device *net_dev, 
	if (is_ofdm && !(ieee->modulation & IEEE80211_OFDM_MODULATION))

		goto out_unlock;



	mac->txrates.default_rate = rate;

	mac->txrates.default_fallback = lower_rate(mac, rate);

	mac->txrates.user_rate = rate;

	ieee80211softmac_recalc_txrates(mac);

	err = 0;



out_unlock: