2007-12-19 00:30:39

by Stefano Brivio

[permalink] [raw]
Subject: [PATCH v3 1/8] mac80211: clean up rate selection

From: Mattias Nissler <[email protected]>

Move some code out of rc80211_simple since it's probably needed for all rate
selection algorithms, and fix iwlwifi accordingly. While at it, clean up the
rate_control_get_rate() interface.

Signed-off-by: Mattias Nissler <[email protected]>
---
drivers/net/wireless/iwlwifi/iwl-3945-rs.c | 44 ++---------------
drivers/net/wireless/iwlwifi/iwl-4965-rs.c | 47 +++---------------
net/mac80211/ieee80211.c | 6 --
net/mac80211/ieee80211_rate.c | 47 ++++++++++++++++++
net/mac80211/ieee80211_rate.h | 73 ++++++++++++++++++-----------
net/mac80211/ieee80211_sta.c | 13 +----
net/mac80211/rc80211_simple.c | 64 ++++---------------------
net/mac80211/tx.c | 42 +++++++---------
8 files changed, 146 insertions(+), 190 deletions(-)

Index: wireless-2.6/net/mac80211/ieee80211.c
===================================================================
--- wireless-2.6.orig/net/mac80211/ieee80211.c
+++ wireless-2.6/net/mac80211/ieee80211.c
@@ -860,10 +860,8 @@ void ieee80211_tx_status(struct ieee8021
sta_info_put(sta);
return;
}
- } else {
- /* FIXME: STUPID to call this with both local and local->mdev */
- rate_control_tx_status(local, local->mdev, skb, status);
- }
+ } else
+ rate_control_tx_status(local->mdev, skb, status);

ieee80211_led_tx(local, 0);

Index: wireless-2.6/net/mac80211/ieee80211_rate.c
===================================================================
--- wireless-2.6.orig/net/mac80211/ieee80211_rate.c
+++ wireless-2.6/net/mac80211/ieee80211_rate.c
@@ -147,6 +147,53 @@ static void rate_control_release(struct
kfree(ctrl_ref);
}

+void rate_control_get_rate(struct net_device *dev,
+ struct ieee80211_hw_mode *mode, struct sk_buff *skb,
+ struct rate_selection *sel)
+{
+ struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
+ struct rate_control_ref *ref = local->rate_ctrl;
+ struct ieee80211_sub_if_data *sdata;
+ struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
+ struct sta_info *sta = sta_info_get(local, hdr->addr1);
+ int i;
+ u16 fc;
+
+ memset(sel, 0, sizeof(struct rate_selection));
+
+ /* Send management frames and broadcast/multicast data using lowest
+ * rate. */
+ fc = le16_to_cpu(hdr->frame_control);
+ if ((fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA ||
+ is_multicast_ether_addr(hdr->addr1))
+ sel->rate = rate_lowest(local, mode, sta);
+
+ /* If a forced rate is in effect, select it. */
+ sdata = IEEE80211_DEV_TO_SUB_IF(dev);
+ if (sdata->bss && sdata->bss->force_unicast_rateidx > -1)
+ sel->rate = &mode->rates[sdata->bss->force_unicast_rateidx];
+
+ /* If we haven't found the rate yet, ask the rate control algo. */
+ if (!sel->rate)
+ ref->ops->get_rate(ref->priv, dev, mode, skb, sel);
+
+ /* Select a non-ERP backup rate. */
+ if (!sel->nonerp) {
+ for (i = 0; i < mode->num_rates - 1; i++) {
+ struct ieee80211_rate *rate = &mode->rates[i];
+ if (sel->rate->rate < rate->rate)
+ break;
+
+ if (rate_supported(sta, mode, i) &&
+ !(rate->flags & IEEE80211_RATE_ERP))
+ sel->nonerp = rate;
+ }
+ }
+
+ if (sta)
+ sta_info_put(sta);
+}
+
struct rate_control_ref *rate_control_get(struct rate_control_ref *ref)
{
kref_get(&ref->kref);
Index: wireless-2.6/net/mac80211/ieee80211_rate.h
===================================================================
--- wireless-2.6.orig/net/mac80211/ieee80211_rate.h
+++ wireless-2.6/net/mac80211/ieee80211_rate.h
@@ -18,31 +18,24 @@
#include "ieee80211_i.h"
#include "sta_info.h"

-#define RATE_CONTROL_NUM_DOWN 20
-#define RATE_CONTROL_NUM_UP 15
-
-
-struct rate_control_extra {
- /* values from rate_control_get_rate() to the caller: */
- struct ieee80211_rate *probe; /* probe with this rate, or NULL for no
- * probing */
+struct rate_selection {
+ /* Selected transmission rate */
+ struct ieee80211_rate *rate;
+ /* Non-ERP rate to use if mac80211 decides it cannot use an ERP rate */
struct ieee80211_rate *nonerp;
-
- /* parameters from the caller to rate_control_get_rate(): */
- struct ieee80211_hw_mode *mode;
- u16 ethertype;
+ /* probe with this rate, or NULL for no probing */
+ struct ieee80211_rate *probe;
};

-
struct rate_control_ops {
struct module *module;
const char *name;
void (*tx_status)(void *priv, struct net_device *dev,
struct sk_buff *skb,
struct ieee80211_tx_status *status);
- struct ieee80211_rate *(*get_rate)(void *priv, struct net_device *dev,
- struct sk_buff *skb,
- struct rate_control_extra *extra);
+ void (*get_rate)(void *priv, struct net_device *dev,
+ struct ieee80211_hw_mode *mode, struct sk_buff *skb,
+ struct rate_selection *sel);
void (*rate_init)(void *priv, void *priv_sta,
struct ieee80211_local *local, struct sta_info *sta);
void (*clear)(void *priv);
@@ -75,25 +68,20 @@ void ieee80211_rate_control_unregister(s
* first available algorithm. */
struct rate_control_ref *rate_control_alloc(const char *name,
struct ieee80211_local *local);
+void rate_control_get_rate(struct net_device *dev,
+ struct ieee80211_hw_mode *mode, struct sk_buff *skb,
+ struct rate_selection *sel);
struct rate_control_ref *rate_control_get(struct rate_control_ref *ref);
void rate_control_put(struct rate_control_ref *ref);

-static inline void rate_control_tx_status(struct ieee80211_local *local,
- struct net_device *dev,
+static inline void rate_control_tx_status(struct net_device *dev,
struct sk_buff *skb,
struct ieee80211_tx_status *status)
{
+ struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
struct rate_control_ref *ref = local->rate_ctrl;
- ref->ops->tx_status(ref->priv, dev, skb, status);
-}

-
-static inline struct ieee80211_rate *
-rate_control_get_rate(struct ieee80211_local *local, struct net_device *dev,
- struct sk_buff *skb, struct rate_control_extra *extra)
-{
- struct rate_control_ref *ref = local->rate_ctrl;
- return ref->ops->get_rate(ref->priv, dev, skb, extra);
+ ref->ops->tx_status(ref->priv, dev, skb, status);
}


@@ -142,6 +130,37 @@ static inline void rate_control_remove_s
#endif
}

+static inline int
+rate_supported(struct sta_info *sta, struct ieee80211_hw_mode *mode, int index)
+{
+ return (sta == NULL || sta->supp_rates & BIT(index)) &&
+ (mode->rates[index].flags & IEEE80211_RATE_SUPPORTED);
+}
+
+static inline int
+rate_lowest_index(struct ieee80211_local *local, struct ieee80211_hw_mode *mode,
+ struct sta_info *sta)
+{
+ int i;
+
+ for (i = 0; i < mode->num_rates; i++) {
+ if (rate_supported(sta, mode, i))
+ return i;
+ }
+
+ /* warn when we cannot find a rate. */
+ WARN_ON(i == 0);
+
+ return 0;
+}
+
+static inline struct ieee80211_rate *
+rate_lowest(struct ieee80211_local *local, struct ieee80211_hw_mode *mode,
+ struct sta_info *sta)
+{
+ return &mode->rates[rate_lowest_index(local, mode, sta)];
+}
+

/* functions for rate control related to a device */
int ieee80211_init_rate_ctrl_alg(struct ieee80211_local *local,
Index: wireless-2.6/net/mac80211/ieee80211_sta.c
===================================================================
--- wireless-2.6.orig/net/mac80211/ieee80211_sta.c
+++ wireless-2.6/net/mac80211/ieee80211_sta.c
@@ -2467,9 +2467,8 @@ static int ieee80211_sta_join_ibss(struc
struct sk_buff *skb;
struct ieee80211_mgmt *mgmt;
struct ieee80211_tx_control control;
- struct ieee80211_rate *rate;
struct ieee80211_hw_mode *mode;
- struct rate_control_extra extra;
+ struct rate_selection ratesel;
u8 *pos;
struct ieee80211_sub_if_data *sdata;

@@ -2554,18 +2553,16 @@ static int ieee80211_sta_join_ibss(struc
}

memset(&control, 0, sizeof(control));
- memset(&extra, 0, sizeof(extra));
- extra.mode = local->oper_hw_mode;
- rate = rate_control_get_rate(local, dev, skb, &extra);
- if (!rate) {
+ rate_control_get_rate(dev, local->oper_hw_mode, skb, &ratesel);
+ if (!ratesel.rate) {
printk(KERN_DEBUG "%s: Failed to determine TX rate "
"for IBSS beacon\n", dev->name);
break;
}
control.tx_rate =
((sdata->flags & IEEE80211_SDATA_SHORT_PREAMBLE) &&
- (rate->flags & IEEE80211_RATE_PREAMBLE2)) ?
- rate->val2 : rate->val;
+ (ratesel.rate->flags & IEEE80211_RATE_PREAMBLE2)) ?
+ ratesel.rate->val2 : ratesel.rate->val;
control.antenna_sel_tx = local->hw.conf.antenna_sel_tx;
control.power_level = local->hw.conf.power_level;
control.flags |= IEEE80211_TXCTL_NO_ACK;
Index: wireless-2.6/net/mac80211/rc80211_simple.c
===================================================================
--- wireless-2.6.orig/net/mac80211/rc80211_simple.c
+++ wireless-2.6/net/mac80211/rc80211_simple.c
@@ -23,6 +23,8 @@
/* This is a minimal implementation of TX rate controlling that can be used
* as the default when no improved mechanisms are available. */

+#define RATE_CONTROL_NUM_DOWN 20
+#define RATE_CONTROL_NUM_UP 15

#define RATE_CONTROL_EMERG_DEC 2
#define RATE_CONTROL_INTERVAL (HZ / 20)
@@ -87,26 +89,6 @@ static void rate_control_rate_dec(struct
}
}

-
-static struct ieee80211_rate *
-rate_control_lowest_rate(struct ieee80211_local *local,
- struct ieee80211_hw_mode *mode)
-{
- int i;
-
- for (i = 0; i < mode->num_rates; i++) {
- struct ieee80211_rate *rate = &mode->rates[i];
-
- if (rate->flags & IEEE80211_RATE_SUPPORTED)
- return rate;
- }
-
- printk(KERN_DEBUG "rate_control_lowest_rate - no supported rates "
- "found\n");
- return &mode->rates[0];
-}
-
-
struct global_rate_control {
int dummy;
};
@@ -216,56 +198,32 @@ static void rate_control_simple_tx_statu
}


-static struct ieee80211_rate *
+static void
rate_control_simple_get_rate(void *priv, struct net_device *dev,
+ struct ieee80211_hw_mode *mode,
struct sk_buff *skb,
- struct rate_control_extra *extra)
+ struct rate_selection *sel)
{
struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
- struct ieee80211_sub_if_data *sdata;
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
- struct ieee80211_hw_mode *mode = extra->mode;
struct sta_info *sta;
- int rateidx, nonerp_idx;
- u16 fc;
-
- memset(extra, 0, sizeof(*extra));
-
- fc = le16_to_cpu(hdr->frame_control);
- if ((fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA ||
- (hdr->addr1[0] & 0x01)) {
- /* Send management frames and broadcast/multicast data using
- * lowest rate. */
- /* TODO: this could probably be improved.. */
- return rate_control_lowest_rate(local, mode);
- }
+ int rateidx;

sta = sta_info_get(local, hdr->addr1);

- if (!sta)
- return rate_control_lowest_rate(local, mode);
-
- sdata = IEEE80211_DEV_TO_SUB_IF(dev);
- if (sdata->bss && sdata->bss->force_unicast_rateidx > -1)
- sta->txrate = sdata->bss->force_unicast_rateidx;
+ if (!sta) {
+ sel->rate = rate_lowest(local, mode, NULL);
+ return;
+ }

rateidx = sta->txrate;

if (rateidx >= mode->num_rates)
rateidx = mode->num_rates - 1;

- sta->last_txrate = rateidx;
- nonerp_idx = rateidx;
- while (nonerp_idx > 0 &&
- ((mode->rates[nonerp_idx].flags & IEEE80211_RATE_ERP) ||
- !(mode->rates[nonerp_idx].flags & IEEE80211_RATE_SUPPORTED) ||
- !(sta->supp_rates & BIT(nonerp_idx))))
- nonerp_idx--;
- extra->nonerp = &mode->rates[nonerp_idx];
-
sta_info_put(sta);

- return &mode->rates[rateidx];
+ sel->rate = &mode->rates[rateidx];
}


Index: wireless-2.6/net/mac80211/tx.c
===================================================================
--- wireless-2.6.orig/net/mac80211/tx.c
+++ wireless-2.6/net/mac80211/tx.c
@@ -569,21 +569,17 @@ ieee80211_tx_h_encrypt(struct ieee80211_
static ieee80211_txrx_result
ieee80211_tx_h_rate_ctrl(struct ieee80211_txrx_data *tx)
{
- struct rate_control_extra extra;
+ struct rate_selection rsel;

if (likely(!tx->u.tx.rate)) {
- memset(&extra, 0, sizeof(extra));
- extra.mode = tx->u.tx.mode;
- extra.ethertype = tx->ethertype;
-
- tx->u.tx.rate = rate_control_get_rate(tx->local, tx->dev,
- tx->skb, &extra);
- if (unlikely(extra.probe != NULL)) {
+ rate_control_get_rate(tx->dev, tx->u.tx.mode, tx->skb, &rsel);
+ tx->u.tx.rate = rsel.rate;
+ if (unlikely(rsel.probe != NULL)) {
tx->u.tx.control->flags |=
IEEE80211_TXCTL_RATE_CTRL_PROBE;
tx->flags |= IEEE80211_TXRXD_TXPROBE_LAST_FRAG;
tx->u.tx.control->alt_retry_rate = tx->u.tx.rate->val;
- tx->u.tx.rate = extra.probe;
+ tx->u.tx.rate = rsel.probe;
} else
tx->u.tx.control->alt_retry_rate = -1;

@@ -594,14 +590,14 @@ ieee80211_tx_h_rate_ctrl(struct ieee8021

if (tx->u.tx.mode->mode == MODE_IEEE80211G &&
(tx->sdata->flags & IEEE80211_SDATA_USE_PROTECTION) &&
- (tx->flags & IEEE80211_TXRXD_FRAGMENTED) && extra.nonerp) {
+ (tx->flags & IEEE80211_TXRXD_FRAGMENTED) && rsel.nonerp) {
tx->u.tx.last_frag_rate = tx->u.tx.rate;
- if (extra.probe)
+ if (rsel.probe)
tx->flags &= ~IEEE80211_TXRXD_TXPROBE_LAST_FRAG;
else
tx->flags |= IEEE80211_TXRXD_TXPROBE_LAST_FRAG;
- tx->u.tx.rate = extra.nonerp;
- tx->u.tx.control->rate = extra.nonerp;
+ tx->u.tx.rate = rsel.nonerp;
+ tx->u.tx.control->rate = rsel.nonerp;
tx->u.tx.control->flags &= ~IEEE80211_TXCTL_RATE_CTRL_PROBE;
} else {
tx->u.tx.last_frag_rate = tx->u.tx.rate;
@@ -1667,8 +1663,7 @@ struct sk_buff *ieee80211_beacon_get(str
struct net_device *bdev;
struct ieee80211_sub_if_data *sdata = NULL;
struct ieee80211_if_ap *ap = NULL;
- struct ieee80211_rate *rate;
- struct rate_control_extra extra;
+ struct rate_selection rsel;
u8 *b_head, *b_tail;
int bh_len, bt_len;

@@ -1712,14 +1707,13 @@ struct sk_buff *ieee80211_beacon_get(str
}

if (control) {
- memset(&extra, 0, sizeof(extra));
- extra.mode = local->oper_hw_mode;
-
- rate = rate_control_get_rate(local, local->mdev, skb, &extra);
- if (!rate) {
+ rate_control_get_rate(local->mdev, local->oper_hw_mode, skb,
+ &rsel);
+ if (!rsel.rate) {
if (net_ratelimit()) {
- printk(KERN_DEBUG "%s: ieee80211_beacon_get: no rate "
- "found\n", wiphy_name(local->hw.wiphy));
+ printk(KERN_DEBUG "%s: ieee80211_beacon_get: "
+ "no rate found\n",
+ wiphy_name(local->hw.wiphy));
}
dev_kfree_skb(skb);
return NULL;
@@ -1727,8 +1721,8 @@ struct sk_buff *ieee80211_beacon_get(str

control->tx_rate =
((sdata->flags & IEEE80211_SDATA_SHORT_PREAMBLE) &&
- (rate->flags & IEEE80211_RATE_PREAMBLE2)) ?
- rate->val2 : rate->val;
+ (rsel.rate->flags & IEEE80211_RATE_PREAMBLE2)) ?
+ rsel.rate->val2 : rsel.rate->val;
control->antenna_sel_tx = local->hw.conf.antenna_sel_tx;
control->power_level = local->hw.conf.power_level;
control->flags |= IEEE80211_TXCTL_NO_ACK;
Index: wireless-2.6/drivers/net/wireless/iwlwifi/iwl-3945-rs.c
===================================================================
--- wireless-2.6.orig/drivers/net/wireless/iwlwifi/iwl-3945-rs.c
+++ wireless-2.6/drivers/net/wireless/iwlwifi/iwl-3945-rs.c
@@ -560,22 +560,6 @@ static void rs_tx_status(void *priv_rate
return;
}

-static struct ieee80211_rate *iwl3945_get_lowest_rate(struct ieee80211_local
- *local)
-{
- struct ieee80211_hw_mode *mode = local->oper_hw_mode;
- int i;
-
- for (i = 0; i < mode->num_rates; i++) {
- struct ieee80211_rate *rate = &mode->rates[i];
-
- if (rate->flags & IEEE80211_RATE_SUPPORTED)
- return rate;
- }
-
- return &mode->rates[0];
-}
-
static u16 iwl3945_get_adjacent_rate(struct iwl3945_rate_scale_priv *rs_priv,
u8 index, u16 rate_mask, int phymode)
{
@@ -654,10 +638,9 @@ static u16 iwl3945_get_adjacent_rate(str
* rate table and must reference the driver allocated rate table
*
*/
-static struct ieee80211_rate *rs_get_rate(void *priv_rate,
- struct net_device *dev,
- struct sk_buff *skb,
- struct rate_control_extra *extra)
+static void rs_get_rate(void *priv_rate, struct net_device *dev,
+ struct ieee80211_hw_mode *mode, struct sk_buff *skb,
+ struct rate_selection *sel)
{
u8 low = IWL_RATE_INVALID;
u8 high = IWL_RATE_INVALID;
@@ -674,32 +657,19 @@ static struct ieee80211_rate *rs_get_rat
struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
struct sta_info *sta;
- u16 fc, rate_mask;
+ u16 rate_mask;
struct iwl3945_priv *priv = (struct iwl3945_priv *)priv_rate;
DECLARE_MAC_BUF(mac);

IWL_DEBUG_RATE("enter\n");

- memset(extra, 0, sizeof(*extra));
-
- fc = le16_to_cpu(hdr->frame_control);
- if (((fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA) ||
- (is_multicast_ether_addr(hdr->addr1))) {
- /* Send management frames and broadcast/multicast data using
- * lowest rate. */
- /* TODO: this could probably be improved.. */
- IWL_DEBUG_RATE("leave: lowest rate (not data or is "
- "multicast)\n");
-
- return iwl3945_get_lowest_rate(local);
- }
-
sta = sta_info_get(local, hdr->addr1);
if (!sta || !sta->rate_ctrl_priv) {
IWL_DEBUG_RATE("leave: No STA priv data to update!\n");
+ sel->rate = rate_lowest(local, local->oper_hw_mode, sta);
if (sta)
sta_info_put(sta);
- return NULL;
+ return;
}

rate_mask = sta->supp_rates;
@@ -844,7 +814,7 @@ static struct ieee80211_rate *rs_get_rat

IWL_DEBUG_RATE("leave: %d\n", index);

- return &priv->ieee_rates[index];
+ sel->rate = &priv->ieee_rates[index];
}

static struct rate_control_ops rs_ops = {
Index: wireless-2.6/drivers/net/wireless/iwlwifi/iwl-4965-rs.c
===================================================================
--- wireless-2.6.orig/drivers/net/wireless/iwlwifi/iwl-4965-rs.c
+++ wireless-2.6/drivers/net/wireless/iwlwifi/iwl-4965-rs.c
@@ -2007,56 +2007,27 @@ static void rs_initialize_lq(struct iwl4
return;
}

-static struct ieee80211_rate *rs_get_lowest_rate(struct ieee80211_local
- *local)
+static void rs_get_rate(void *priv_rate, struct net_device *dev,
+ struct ieee80211_hw_mode *mode, struct sk_buff *skb,
+ struct rate_selection *sel)
{
- struct ieee80211_hw_mode *mode = local->oper_hw_mode;
- int i;
-
- for (i = 0; i < mode->num_rates; i++) {
- struct ieee80211_rate *rate = &mode->rates[i];
-
- if (rate->flags & IEEE80211_RATE_SUPPORTED)
- return rate;
- }
-
- return &mode->rates[0];
-}
-
-static struct ieee80211_rate *rs_get_rate(void *priv_rate,
- struct net_device *dev,
- struct sk_buff *skb,
- struct rate_control_extra
- *extra)
-{
-
int i;
struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
struct ieee80211_conf *conf = &local->hw.conf;
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
struct sta_info *sta;
- u16 fc;
struct iwl4965_priv *priv = (struct iwl4965_priv *)priv_rate;
struct iwl4965_rate_scale_priv *lq;

IWL_DEBUG_RATE_LIMIT("rate scale calculate new rate for skb\n");

- memset(extra, 0, sizeof(*extra));
-
- fc = le16_to_cpu(hdr->frame_control);
- if (!ieee80211_is_data(fc) || is_multicast_ether_addr(hdr->addr1)) {
- /* Send management frames and broadcast/multicast data using
- * lowest rate. */
- /* TODO: this could probably be improved.. */
- return rs_get_lowest_rate(local);
- }
-
sta = sta_info_get(local, hdr->addr1);

if (!sta || !sta->rate_ctrl_priv) {
+ sel->rate = rate_lowest(local, local->oper_hw_mode, sta);
if (sta)
sta_info_put(sta);
- return rs_get_lowest_rate(local);
+ return;
}

lq = (struct iwl4965_rate_scale_priv *)sta->rate_ctrl_priv;
@@ -2083,11 +2054,13 @@ static struct ieee80211_rate *rs_get_rat
}

done:
+ if ((i < 0) || (i > IWL_RATE_COUNT)) {
+ sel->rate = rate_lowest(local, local->oper_hw_mode, sta);
+ return;
+ }
sta_info_put(sta);
- if ((i < 0) || (i > IWL_RATE_COUNT))
- return rs_get_lowest_rate(local);

- return &priv->ieee_rates[i];
+ sel->rate = &priv->ieee_rates[i];
}

static void *rs_alloc_sta(void *priv, gfp_t gfp)

--
Ciao
Stefano


2007-12-19 16:43:16

by Johannes Berg

[permalink] [raw]
Subject: Re: [PATCH v3 1/8] mac80211: clean up rate selection


> +static inline int
> +rate_lowest_index(struct ieee80211_local *local, struct ieee80211_hw_mode *mode,
> + struct sta_info *sta)
> +{
> + int i;
> +
> + for (i = 0; i < mode->num_rates; i++) {
> + if (rate_supported(sta, mode, i))
> + return i;
> + }
> +
> + /* warn when we cannot find a rate. */
> + WARN_ON(i == 0);
> +
> + return 0;
> +}

That doesn't look right. Shouldn't it be WARN_ON(1)? Not that it can
ever happen with proper drivers...

Other than that, looks ok to me.

johannes


Attachments:
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This is a digitally signed message part

2007-12-20 12:55:53

by Stefano Brivio

[permalink] [raw]
Subject: [PATCH v4 1/8] mac80211: clean up rate selection

From: Mattias Nissler <[email protected]>

Move some code out of rc80211_simple since it's probably needed for all rate
selection algorithms, and fix iwlwifi accordingly. While at it, clean up the
rate_control_get_rate() interface.

Signed-off-by: Stefano Brivio <[email protected]>
---
drivers/net/wireless/iwlwifi/iwl-3945-rs.c | 44 ++---------------
drivers/net/wireless/iwlwifi/iwl-4965-rs.c | 47 +++---------------
net/mac80211/ieee80211.c | 6 --
net/mac80211/ieee80211_rate.c | 47 ++++++++++++++++++
net/mac80211/ieee80211_rate.h | 73 ++++++++++++++++++-----------
net/mac80211/ieee80211_sta.c | 13 +----
net/mac80211/rc80211_simple.c | 64 ++++---------------------
net/mac80211/tx.c | 42 +++++++---------
8 files changed, 146 insertions(+), 190 deletions(-)

Index: wireless-2.6/net/mac80211/ieee80211.c
===================================================================
--- wireless-2.6.orig/net/mac80211/ieee80211.c
+++ wireless-2.6/net/mac80211/ieee80211.c
@@ -860,10 +860,8 @@ void ieee80211_tx_status(struct ieee8021
sta_info_put(sta);
return;
}
- } else {
- /* FIXME: STUPID to call this with both local and local->mdev */
- rate_control_tx_status(local, local->mdev, skb, status);
- }
+ } else
+ rate_control_tx_status(local->mdev, skb, status);

ieee80211_led_tx(local, 0);

Index: wireless-2.6/net/mac80211/ieee80211_rate.c
===================================================================
--- wireless-2.6.orig/net/mac80211/ieee80211_rate.c
+++ wireless-2.6/net/mac80211/ieee80211_rate.c
@@ -147,6 +147,53 @@ static void rate_control_release(struct
kfree(ctrl_ref);
}

+void rate_control_get_rate(struct net_device *dev,
+ struct ieee80211_hw_mode *mode, struct sk_buff *skb,
+ struct rate_selection *sel)
+{
+ struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
+ struct rate_control_ref *ref = local->rate_ctrl;
+ struct ieee80211_sub_if_data *sdata;
+ struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
+ struct sta_info *sta = sta_info_get(local, hdr->addr1);
+ int i;
+ u16 fc;
+
+ memset(sel, 0, sizeof(struct rate_selection));
+
+ /* Send management frames and broadcast/multicast data using lowest
+ * rate. */
+ fc = le16_to_cpu(hdr->frame_control);
+ if ((fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA ||
+ is_multicast_ether_addr(hdr->addr1))
+ sel->rate = rate_lowest(local, mode, sta);
+
+ /* If a forced rate is in effect, select it. */
+ sdata = IEEE80211_DEV_TO_SUB_IF(dev);
+ if (sdata->bss && sdata->bss->force_unicast_rateidx > -1)
+ sel->rate = &mode->rates[sdata->bss->force_unicast_rateidx];
+
+ /* If we haven't found the rate yet, ask the rate control algo. */
+ if (!sel->rate)
+ ref->ops->get_rate(ref->priv, dev, mode, skb, sel);
+
+ /* Select a non-ERP backup rate. */
+ if (!sel->nonerp) {
+ for (i = 0; i < mode->num_rates - 1; i++) {
+ struct ieee80211_rate *rate = &mode->rates[i];
+ if (sel->rate->rate < rate->rate)
+ break;
+
+ if (rate_supported(sta, mode, i) &&
+ !(rate->flags & IEEE80211_RATE_ERP))
+ sel->nonerp = rate;
+ }
+ }
+
+ if (sta)
+ sta_info_put(sta);
+}
+
struct rate_control_ref *rate_control_get(struct rate_control_ref *ref)
{
kref_get(&ref->kref);
Index: wireless-2.6/net/mac80211/ieee80211_rate.h
===================================================================
--- wireless-2.6.orig/net/mac80211/ieee80211_rate.h
+++ wireless-2.6/net/mac80211/ieee80211_rate.h
@@ -18,31 +18,24 @@
#include "ieee80211_i.h"
#include "sta_info.h"

-#define RATE_CONTROL_NUM_DOWN 20
-#define RATE_CONTROL_NUM_UP 15
-
-
-struct rate_control_extra {
- /* values from rate_control_get_rate() to the caller: */
- struct ieee80211_rate *probe; /* probe with this rate, or NULL for no
- * probing */
+struct rate_selection {
+ /* Selected transmission rate */
+ struct ieee80211_rate *rate;
+ /* Non-ERP rate to use if mac80211 decides it cannot use an ERP rate */
struct ieee80211_rate *nonerp;
-
- /* parameters from the caller to rate_control_get_rate(): */
- struct ieee80211_hw_mode *mode;
- u16 ethertype;
+ /* probe with this rate, or NULL for no probing */
+ struct ieee80211_rate *probe;
};

-
struct rate_control_ops {
struct module *module;
const char *name;
void (*tx_status)(void *priv, struct net_device *dev,
struct sk_buff *skb,
struct ieee80211_tx_status *status);
- struct ieee80211_rate *(*get_rate)(void *priv, struct net_device *dev,
- struct sk_buff *skb,
- struct rate_control_extra *extra);
+ void (*get_rate)(void *priv, struct net_device *dev,
+ struct ieee80211_hw_mode *mode, struct sk_buff *skb,
+ struct rate_selection *sel);
void (*rate_init)(void *priv, void *priv_sta,
struct ieee80211_local *local, struct sta_info *sta);
void (*clear)(void *priv);
@@ -75,25 +68,20 @@ void ieee80211_rate_control_unregister(s
* first available algorithm. */
struct rate_control_ref *rate_control_alloc(const char *name,
struct ieee80211_local *local);
+void rate_control_get_rate(struct net_device *dev,
+ struct ieee80211_hw_mode *mode, struct sk_buff *skb,
+ struct rate_selection *sel);
struct rate_control_ref *rate_control_get(struct rate_control_ref *ref);
void rate_control_put(struct rate_control_ref *ref);

-static inline void rate_control_tx_status(struct ieee80211_local *local,
- struct net_device *dev,
+static inline void rate_control_tx_status(struct net_device *dev,
struct sk_buff *skb,
struct ieee80211_tx_status *status)
{
+ struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
struct rate_control_ref *ref = local->rate_ctrl;
- ref->ops->tx_status(ref->priv, dev, skb, status);
-}

-
-static inline struct ieee80211_rate *
-rate_control_get_rate(struct ieee80211_local *local, struct net_device *dev,
- struct sk_buff *skb, struct rate_control_extra *extra)
-{
- struct rate_control_ref *ref = local->rate_ctrl;
- return ref->ops->get_rate(ref->priv, dev, skb, extra);
+ ref->ops->tx_status(ref->priv, dev, skb, status);
}


@@ -142,6 +130,37 @@ static inline void rate_control_remove_s
#endif
}

+static inline int
+rate_supported(struct sta_info *sta, struct ieee80211_hw_mode *mode, int index)
+{
+ return (sta == NULL || sta->supp_rates & BIT(index)) &&
+ (mode->rates[index].flags & IEEE80211_RATE_SUPPORTED);
+}
+
+static inline int
+rate_lowest_index(struct ieee80211_local *local, struct ieee80211_hw_mode *mode,
+ struct sta_info *sta)
+{
+ int i;
+
+ for (i = 0; i < mode->num_rates; i++) {
+ if (rate_supported(sta, mode, i))
+ return i;
+ }
+
+ /* warn when we cannot find a rate. */
+ WARN_ON(1);
+
+ return 0;
+}
+
+static inline struct ieee80211_rate *
+rate_lowest(struct ieee80211_local *local, struct ieee80211_hw_mode *mode,
+ struct sta_info *sta)
+{
+ return &mode->rates[rate_lowest_index(local, mode, sta)];
+}
+

/* functions for rate control related to a device */
int ieee80211_init_rate_ctrl_alg(struct ieee80211_local *local,
Index: wireless-2.6/net/mac80211/ieee80211_sta.c
===================================================================
--- wireless-2.6.orig/net/mac80211/ieee80211_sta.c
+++ wireless-2.6/net/mac80211/ieee80211_sta.c
@@ -2467,9 +2467,8 @@ static int ieee80211_sta_join_ibss(struc
struct sk_buff *skb;
struct ieee80211_mgmt *mgmt;
struct ieee80211_tx_control control;
- struct ieee80211_rate *rate;
struct ieee80211_hw_mode *mode;
- struct rate_control_extra extra;
+ struct rate_selection ratesel;
u8 *pos;
struct ieee80211_sub_if_data *sdata;

@@ -2554,18 +2553,16 @@ static int ieee80211_sta_join_ibss(struc
}

memset(&control, 0, sizeof(control));
- memset(&extra, 0, sizeof(extra));
- extra.mode = local->oper_hw_mode;
- rate = rate_control_get_rate(local, dev, skb, &extra);
- if (!rate) {
+ rate_control_get_rate(dev, local->oper_hw_mode, skb, &ratesel);
+ if (!ratesel.rate) {
printk(KERN_DEBUG "%s: Failed to determine TX rate "
"for IBSS beacon\n", dev->name);
break;
}
control.tx_rate =
((sdata->flags & IEEE80211_SDATA_SHORT_PREAMBLE) &&
- (rate->flags & IEEE80211_RATE_PREAMBLE2)) ?
- rate->val2 : rate->val;
+ (ratesel.rate->flags & IEEE80211_RATE_PREAMBLE2)) ?
+ ratesel.rate->val2 : ratesel.rate->val;
control.antenna_sel_tx = local->hw.conf.antenna_sel_tx;
control.power_level = local->hw.conf.power_level;
control.flags |= IEEE80211_TXCTL_NO_ACK;
Index: wireless-2.6/net/mac80211/rc80211_simple.c
===================================================================
--- wireless-2.6.orig/net/mac80211/rc80211_simple.c
+++ wireless-2.6/net/mac80211/rc80211_simple.c
@@ -23,6 +23,8 @@
/* This is a minimal implementation of TX rate controlling that can be used
* as the default when no improved mechanisms are available. */

+#define RATE_CONTROL_NUM_DOWN 20
+#define RATE_CONTROL_NUM_UP 15

#define RATE_CONTROL_EMERG_DEC 2
#define RATE_CONTROL_INTERVAL (HZ / 20)
@@ -87,26 +89,6 @@ static void rate_control_rate_dec(struct
}
}

-
-static struct ieee80211_rate *
-rate_control_lowest_rate(struct ieee80211_local *local,
- struct ieee80211_hw_mode *mode)
-{
- int i;
-
- for (i = 0; i < mode->num_rates; i++) {
- struct ieee80211_rate *rate = &mode->rates[i];
-
- if (rate->flags & IEEE80211_RATE_SUPPORTED)
- return rate;
- }
-
- printk(KERN_DEBUG "rate_control_lowest_rate - no supported rates "
- "found\n");
- return &mode->rates[0];
-}
-
-
struct global_rate_control {
int dummy;
};
@@ -216,56 +198,32 @@ static void rate_control_simple_tx_statu
}


-static struct ieee80211_rate *
+static void
rate_control_simple_get_rate(void *priv, struct net_device *dev,
+ struct ieee80211_hw_mode *mode,
struct sk_buff *skb,
- struct rate_control_extra *extra)
+ struct rate_selection *sel)
{
struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
- struct ieee80211_sub_if_data *sdata;
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
- struct ieee80211_hw_mode *mode = extra->mode;
struct sta_info *sta;
- int rateidx, nonerp_idx;
- u16 fc;
-
- memset(extra, 0, sizeof(*extra));
-
- fc = le16_to_cpu(hdr->frame_control);
- if ((fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA ||
- (hdr->addr1[0] & 0x01)) {
- /* Send management frames and broadcast/multicast data using
- * lowest rate. */
- /* TODO: this could probably be improved.. */
- return rate_control_lowest_rate(local, mode);
- }
+ int rateidx;

sta = sta_info_get(local, hdr->addr1);

- if (!sta)
- return rate_control_lowest_rate(local, mode);
-
- sdata = IEEE80211_DEV_TO_SUB_IF(dev);
- if (sdata->bss && sdata->bss->force_unicast_rateidx > -1)
- sta->txrate = sdata->bss->force_unicast_rateidx;
+ if (!sta) {
+ sel->rate = rate_lowest(local, mode, NULL);
+ return;
+ }

rateidx = sta->txrate;

if (rateidx >= mode->num_rates)
rateidx = mode->num_rates - 1;

- sta->last_txrate = rateidx;
- nonerp_idx = rateidx;
- while (nonerp_idx > 0 &&
- ((mode->rates[nonerp_idx].flags & IEEE80211_RATE_ERP) ||
- !(mode->rates[nonerp_idx].flags & IEEE80211_RATE_SUPPORTED) ||
- !(sta->supp_rates & BIT(nonerp_idx))))
- nonerp_idx--;
- extra->nonerp = &mode->rates[nonerp_idx];
-
sta_info_put(sta);

- return &mode->rates[rateidx];
+ sel->rate = &mode->rates[rateidx];
}


Index: wireless-2.6/net/mac80211/tx.c
===================================================================
--- wireless-2.6.orig/net/mac80211/tx.c
+++ wireless-2.6/net/mac80211/tx.c
@@ -569,21 +569,17 @@ ieee80211_tx_h_encrypt(struct ieee80211_
static ieee80211_txrx_result
ieee80211_tx_h_rate_ctrl(struct ieee80211_txrx_data *tx)
{
- struct rate_control_extra extra;
+ struct rate_selection rsel;

if (likely(!tx->u.tx.rate)) {
- memset(&extra, 0, sizeof(extra));
- extra.mode = tx->u.tx.mode;
- extra.ethertype = tx->ethertype;
-
- tx->u.tx.rate = rate_control_get_rate(tx->local, tx->dev,
- tx->skb, &extra);
- if (unlikely(extra.probe != NULL)) {
+ rate_control_get_rate(tx->dev, tx->u.tx.mode, tx->skb, &rsel);
+ tx->u.tx.rate = rsel.rate;
+ if (unlikely(rsel.probe != NULL)) {
tx->u.tx.control->flags |=
IEEE80211_TXCTL_RATE_CTRL_PROBE;
tx->flags |= IEEE80211_TXRXD_TXPROBE_LAST_FRAG;
tx->u.tx.control->alt_retry_rate = tx->u.tx.rate->val;
- tx->u.tx.rate = extra.probe;
+ tx->u.tx.rate = rsel.probe;
} else
tx->u.tx.control->alt_retry_rate = -1;

@@ -594,14 +590,14 @@ ieee80211_tx_h_rate_ctrl(struct ieee8021

if (tx->u.tx.mode->mode == MODE_IEEE80211G &&
(tx->sdata->flags & IEEE80211_SDATA_USE_PROTECTION) &&
- (tx->flags & IEEE80211_TXRXD_FRAGMENTED) && extra.nonerp) {
+ (tx->flags & IEEE80211_TXRXD_FRAGMENTED) && rsel.nonerp) {
tx->u.tx.last_frag_rate = tx->u.tx.rate;
- if (extra.probe)
+ if (rsel.probe)
tx->flags &= ~IEEE80211_TXRXD_TXPROBE_LAST_FRAG;
else
tx->flags |= IEEE80211_TXRXD_TXPROBE_LAST_FRAG;
- tx->u.tx.rate = extra.nonerp;
- tx->u.tx.control->rate = extra.nonerp;
+ tx->u.tx.rate = rsel.nonerp;
+ tx->u.tx.control->rate = rsel.nonerp;
tx->u.tx.control->flags &= ~IEEE80211_TXCTL_RATE_CTRL_PROBE;
} else {
tx->u.tx.last_frag_rate = tx->u.tx.rate;
@@ -1667,8 +1663,7 @@ struct sk_buff *ieee80211_beacon_get(str
struct net_device *bdev;
struct ieee80211_sub_if_data *sdata = NULL;
struct ieee80211_if_ap *ap = NULL;
- struct ieee80211_rate *rate;
- struct rate_control_extra extra;
+ struct rate_selection rsel;
u8 *b_head, *b_tail;
int bh_len, bt_len;

@@ -1712,14 +1707,13 @@ struct sk_buff *ieee80211_beacon_get(str
}

if (control) {
- memset(&extra, 0, sizeof(extra));
- extra.mode = local->oper_hw_mode;
-
- rate = rate_control_get_rate(local, local->mdev, skb, &extra);
- if (!rate) {
+ rate_control_get_rate(local->mdev, local->oper_hw_mode, skb,
+ &rsel);
+ if (!rsel.rate) {
if (net_ratelimit()) {
- printk(KERN_DEBUG "%s: ieee80211_beacon_get: no rate "
- "found\n", wiphy_name(local->hw.wiphy));
+ printk(KERN_DEBUG "%s: ieee80211_beacon_get: "
+ "no rate found\n",
+ wiphy_name(local->hw.wiphy));
}
dev_kfree_skb(skb);
return NULL;
@@ -1727,8 +1721,8 @@ struct sk_buff *ieee80211_beacon_get(str

control->tx_rate =
((sdata->flags & IEEE80211_SDATA_SHORT_PREAMBLE) &&
- (rate->flags & IEEE80211_RATE_PREAMBLE2)) ?
- rate->val2 : rate->val;
+ (rsel.rate->flags & IEEE80211_RATE_PREAMBLE2)) ?
+ rsel.rate->val2 : rsel.rate->val;
control->antenna_sel_tx = local->hw.conf.antenna_sel_tx;
control->power_level = local->hw.conf.power_level;
control->flags |= IEEE80211_TXCTL_NO_ACK;
Index: wireless-2.6/drivers/net/wireless/iwlwifi/iwl-3945-rs.c
===================================================================
--- wireless-2.6.orig/drivers/net/wireless/iwlwifi/iwl-3945-rs.c
+++ wireless-2.6/drivers/net/wireless/iwlwifi/iwl-3945-rs.c
@@ -560,22 +560,6 @@ static void rs_tx_status(void *priv_rate
return;
}

-static struct ieee80211_rate *iwl3945_get_lowest_rate(struct ieee80211_local
- *local)
-{
- struct ieee80211_hw_mode *mode = local->oper_hw_mode;
- int i;
-
- for (i = 0; i < mode->num_rates; i++) {
- struct ieee80211_rate *rate = &mode->rates[i];
-
- if (rate->flags & IEEE80211_RATE_SUPPORTED)
- return rate;
- }
-
- return &mode->rates[0];
-}
-
static u16 iwl3945_get_adjacent_rate(struct iwl3945_rate_scale_priv *rs_priv,
u8 index, u16 rate_mask, int phymode)
{
@@ -654,10 +638,9 @@ static u16 iwl3945_get_adjacent_rate(str
* rate table and must reference the driver allocated rate table
*
*/
-static struct ieee80211_rate *rs_get_rate(void *priv_rate,
- struct net_device *dev,
- struct sk_buff *skb,
- struct rate_control_extra *extra)
+static void rs_get_rate(void *priv_rate, struct net_device *dev,
+ struct ieee80211_hw_mode *mode, struct sk_buff *skb,
+ struct rate_selection *sel)
{
u8 low = IWL_RATE_INVALID;
u8 high = IWL_RATE_INVALID;
@@ -674,32 +657,19 @@ static struct ieee80211_rate *rs_get_rat
struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
struct sta_info *sta;
- u16 fc, rate_mask;
+ u16 rate_mask;
struct iwl3945_priv *priv = (struct iwl3945_priv *)priv_rate;
DECLARE_MAC_BUF(mac);

IWL_DEBUG_RATE("enter\n");

- memset(extra, 0, sizeof(*extra));
-
- fc = le16_to_cpu(hdr->frame_control);
- if (((fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA) ||
- (is_multicast_ether_addr(hdr->addr1))) {
- /* Send management frames and broadcast/multicast data using
- * lowest rate. */
- /* TODO: this could probably be improved.. */
- IWL_DEBUG_RATE("leave: lowest rate (not data or is "
- "multicast)\n");
-
- return iwl3945_get_lowest_rate(local);
- }
-
sta = sta_info_get(local, hdr->addr1);
if (!sta || !sta->rate_ctrl_priv) {
IWL_DEBUG_RATE("leave: No STA priv data to update!\n");
+ sel->rate = rate_lowest(local, local->oper_hw_mode, sta);
if (sta)
sta_info_put(sta);
- return NULL;
+ return;
}

rate_mask = sta->supp_rates;
@@ -844,7 +814,7 @@ static struct ieee80211_rate *rs_get_rat

IWL_DEBUG_RATE("leave: %d\n", index);

- return &priv->ieee_rates[index];
+ sel->rate = &priv->ieee_rates[index];
}

static struct rate_control_ops rs_ops = {
Index: wireless-2.6/drivers/net/wireless/iwlwifi/iwl-4965-rs.c
===================================================================
--- wireless-2.6.orig/drivers/net/wireless/iwlwifi/iwl-4965-rs.c
+++ wireless-2.6/drivers/net/wireless/iwlwifi/iwl-4965-rs.c
@@ -2007,56 +2007,27 @@ static void rs_initialize_lq(struct iwl4
return;
}

-static struct ieee80211_rate *rs_get_lowest_rate(struct ieee80211_local
- *local)
+static void rs_get_rate(void *priv_rate, struct net_device *dev,
+ struct ieee80211_hw_mode *mode, struct sk_buff *skb,
+ struct rate_selection *sel)
{
- struct ieee80211_hw_mode *mode = local->oper_hw_mode;
- int i;
-
- for (i = 0; i < mode->num_rates; i++) {
- struct ieee80211_rate *rate = &mode->rates[i];
-
- if (rate->flags & IEEE80211_RATE_SUPPORTED)
- return rate;
- }
-
- return &mode->rates[0];
-}
-
-static struct ieee80211_rate *rs_get_rate(void *priv_rate,
- struct net_device *dev,
- struct sk_buff *skb,
- struct rate_control_extra
- *extra)
-{
-
int i;
struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
struct ieee80211_conf *conf = &local->hw.conf;
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
struct sta_info *sta;
- u16 fc;
struct iwl4965_priv *priv = (struct iwl4965_priv *)priv_rate;
struct iwl4965_rate_scale_priv *lq;

IWL_DEBUG_RATE_LIMIT("rate scale calculate new rate for skb\n");

- memset(extra, 0, sizeof(*extra));
-
- fc = le16_to_cpu(hdr->frame_control);
- if (!ieee80211_is_data(fc) || is_multicast_ether_addr(hdr->addr1)) {
- /* Send management frames and broadcast/multicast data using
- * lowest rate. */
- /* TODO: this could probably be improved.. */
- return rs_get_lowest_rate(local);
- }
-
sta = sta_info_get(local, hdr->addr1);

if (!sta || !sta->rate_ctrl_priv) {
+ sel->rate = rate_lowest(local, local->oper_hw_mode, sta);
if (sta)
sta_info_put(sta);
- return rs_get_lowest_rate(local);
+ return;
}

lq = (struct iwl4965_rate_scale_priv *)sta->rate_ctrl_priv;
@@ -2083,11 +2054,13 @@ static struct ieee80211_rate *rs_get_rat
}

done:
+ if ((i < 0) || (i > IWL_RATE_COUNT)) {
+ sel->rate = rate_lowest(local, local->oper_hw_mode, sta);
+ return;
+ }
sta_info_put(sta);
- if ((i < 0) || (i > IWL_RATE_COUNT))
- return rs_get_lowest_rate(local);

- return &priv->ieee_rates[i];
+ sel->rate = &priv->ieee_rates[i];
}

static void *rs_alloc_sta(void *priv, gfp_t gfp)


--
Ciao
Stefano