2008-12-13 13:14:23

by Christian Lamparter

[permalink] [raw]
Subject: [PATCH] p54: move statistic timer update routine into a workqueue

This patch moves a good chunk of code from the former statistic update
timer routine into a workqueue, which is kindly provided by mac80211.

Also as a nice side-effect we can lay the foundation for other
essential housekeeping features we want to do in the future.
e.g:
- drain the (clogged) tx_queue.
- initiate bursts.

Signed-off-by: Christian Lamparter <[email protected]>
---
diff -Nurp a/drivers/net/wireless/p54/p54common.c b/drivers/net/wireless/p54/p54common.c
--- a/drivers/net/wireless/p54/p54common.c 2008-12-12 23:26:28.000000000 +0100
+++ b/drivers/net/wireless/p54/p54common.c 2008-12-13 13:36:02.000000000 +0100
@@ -590,6 +590,9 @@ static int p54_rx_data(struct ieee80211_

ieee80211_rx_irqsafe(dev, skb, &rx_status);

+ queue_delayed_work(dev->workqueue, &priv->work,
+ msecs_to_jiffies(P54_STATISTICS_UPDATE));
+
return -1;
}

@@ -653,6 +656,27 @@ void p54_free_skb(struct ieee80211_hw *d
}
EXPORT_SYMBOL_GPL(p54_free_skb);

+static struct sk_buff *p54_find_tx_entry(struct ieee80211_hw *dev,
+ __le32 req_id)
+{
+ struct p54_common *priv = dev->priv;
+ struct sk_buff *entry = priv->tx_queue.next;
+ unsigned long flags;
+
+ spin_lock_irqsave(&priv->tx_queue.lock, flags);
+ while (entry != (struct sk_buff *)&priv->tx_queue) {
+ struct p54_hdr *hdr = (struct p54_hdr *) entry->data;
+
+ if (hdr->req_id == req_id) {
+ spin_unlock_irqrestore(&priv->tx_queue.lock, flags);
+ return entry;
+ }
+ entry = entry->next;
+ }
+ spin_unlock_irqrestore(&priv->tx_queue.lock, flags);
+ return NULL;
+}
+
static void p54_rx_frame_sent(struct ieee80211_hw *dev, struct sk_buff *skb)
{
struct p54_common *priv = dev->priv;
@@ -776,8 +800,12 @@ static void p54_rx_stats(struct ieee8021
struct p54_common *priv = dev->priv;
struct p54_hdr *hdr = (struct p54_hdr *) skb->data;
struct p54_statistics *stats = (struct p54_statistics *) hdr->data;
- u32 tsf32 = le32_to_cpu(stats->tsf32);
+ u32 tsf32;

+ if (unlikely(priv->mode == NL80211_IFTYPE_UNSPECIFIED))
+ return ;
+
+ tsf32 = le32_to_cpu(stats->tsf32);
if (tsf32 < priv->tsf_low32)
priv->tsf_high32++;
priv->tsf_low32 = tsf32;
@@ -787,9 +815,8 @@ static void p54_rx_stats(struct ieee8021
priv->stats.dot11FCSErrorCount = le32_to_cpu(stats->rx_bad_fcs);

priv->noise = p54_rssi_to_dbm(dev, le32_to_cpu(stats->noise));
- complete(&priv->stats_comp);

- mod_timer(&priv->stats_timer, jiffies + 5 * HZ);
+ p54_free_skb(dev, p54_find_tx_entry(dev, hdr->req_id));
}

static void p54_rx_trap(struct ieee80211_hw *dev, struct sk_buff *skb)
@@ -898,6 +925,8 @@ static int p54_assign_address(struct iee
* have a few spare slots for control frames left.
*/
ieee80211_stop_queues(dev);
+ queue_delayed_work(dev->workqueue, &priv->work,
+ msecs_to_jiffies(P54_TX_TIMEOUT));

if (unlikely(left == 32)) {
/*
@@ -1355,6 +1384,10 @@ static int p54_tx(struct ieee80211_hw *d
if (unlikely(p54_assign_address(dev, skb, hdr, skb->len + tim_len)))
goto err;
priv->tx(dev, skb, 0);
+
+ queue_delayed_work(dev->workqueue, &priv->work,
+ msecs_to_jiffies(P54_TX_FRAME_LIFETIME));
+
return 0;

err:
@@ -1580,20 +1613,6 @@ static int p54_set_edcf(struct ieee80211
return 0;
}

-static int p54_init_stats(struct ieee80211_hw *dev)
-{
- struct p54_common *priv = dev->priv;
-
- priv->cached_stats = p54_alloc_skb(dev, P54_HDR_FLAG_CONTROL,
- sizeof(struct p54_hdr) + sizeof(struct p54_statistics),
- P54_CONTROL_TYPE_STAT_READBACK, GFP_KERNEL);
- if (!priv->cached_stats)
- return -ENOMEM;
-
- mod_timer(&priv->stats_timer, jiffies + HZ);
- return 0;
-}
-
static int p54_beacon_tim(struct sk_buff *skb)
{
/*
@@ -1687,9 +1706,6 @@ static int p54_start(struct ieee80211_hw
err = p54_set_edcf(dev);
if (err)
goto out;
- err = p54_init_stats(dev);
- if (err)
- goto out;

memset(priv->bssid, ~0, ETH_ALEN);
priv->mode = NL80211_IFTYPE_MONITOR;
@@ -1699,6 +1715,8 @@ static int p54_start(struct ieee80211_hw
goto out;
}

+ queue_delayed_work(dev->workqueue, &priv->work, 0);
+
out:
mutex_unlock(&priv->conf_mutex);
return err;
@@ -1711,9 +1729,7 @@ static void p54_stop(struct ieee80211_hw

mutex_lock(&priv->conf_mutex);
priv->mode = NL80211_IFTYPE_UNSPECIFIED;
- del_timer(&priv->stats_timer);
- p54_free_skb(dev, priv->cached_stats);
- priv->cached_stats = NULL;
+ cancel_delayed_work_sync(&priv->work);
if (priv->cached_beacon)
p54_tx_cancel(dev, priv->cached_beacon);

@@ -1890,14 +1906,29 @@ static int p54_init_xbow_synth(struct ie
return 0;
}

-static void p54_statistics_timer(unsigned long data)
+static void p54_work(struct work_struct *work)
{
- struct ieee80211_hw *dev = (struct ieee80211_hw *) data;
- struct p54_common *priv = dev->priv;
+ struct p54_common *priv = container_of(work, struct p54_common,
+ work.work);
+ struct ieee80211_hw *dev = priv->hw;
+ struct sk_buff *skb;
+
+ if (unlikely(priv->mode == NL80211_IFTYPE_UNSPECIFIED))
+ return ;
+
+ /*
+ * TODO: walk through tx_queue and do the following tasks
+ * 1. initiate bursts.
+ * 2. cancel stuck frames / reset the device if necessary.
+ */

- BUG_ON(!priv->cached_stats);
+ skb = p54_alloc_skb(dev, P54_HDR_FLAG_CONTROL, sizeof(struct p54_hdr) +
+ sizeof(struct p54_statistics),
+ P54_CONTROL_TYPE_STAT_READBACK, GFP_KERNEL);
+ if (!skb)
+ return ;

- priv->tx(dev, priv->cached_stats, 0);
+ priv->tx(dev, skb, 0);
}

static int p54_get_stats(struct ieee80211_hw *dev,
@@ -1905,17 +1936,7 @@ static int p54_get_stats(struct ieee8021
{
struct p54_common *priv = dev->priv;

- del_timer(&priv->stats_timer);
- p54_statistics_timer((unsigned long)dev);
-
- if (!wait_for_completion_interruptible_timeout(&priv->stats_comp, HZ)) {
- printk(KERN_ERR "%s: device does not respond!\n",
- wiphy_name(dev->wiphy));
- return -EBUSY;
- }
-
memcpy(stats, &priv->stats, sizeof(*stats));
-
return 0;
}

@@ -2073,6 +2094,7 @@ struct ieee80211_hw *p54_init_common(siz
return NULL;

priv = dev->priv;
+ priv->hw = dev;
priv->mode = NL80211_IFTYPE_UNSPECIFIED;
priv->basic_rate_mask = 0x15f;
skb_queue_head_init(&priv->tx_queue);
@@ -2108,9 +2130,7 @@ struct ieee80211_hw *p54_init_common(siz

mutex_init(&priv->conf_mutex);
init_completion(&priv->eeprom_comp);
- init_completion(&priv->stats_comp);
- setup_timer(&priv->stats_timer, p54_statistics_timer,
- (unsigned long)dev);
+ INIT_DELAYED_WORK(&priv->work, p54_work);

return dev;
}
@@ -2119,8 +2139,6 @@ EXPORT_SYMBOL_GPL(p54_init_common);
void p54_free_common(struct ieee80211_hw *dev)
{
struct p54_common *priv = dev->priv;
- del_timer(&priv->stats_timer);
- kfree_skb(priv->cached_stats);
kfree(priv->iq_autocal);
kfree(priv->output_limit);
kfree(priv->curve_data);
diff -Nurp a/drivers/net/wireless/p54/p54common.h b/drivers/net/wireless/p54/p54common.h
--- a/drivers/net/wireless/p54/p54common.h 2008-12-12 23:26:30.000000000 +0100
+++ b/drivers/net/wireless/p54/p54common.h 2008-12-13 13:01:51.000000000 +0100
@@ -355,6 +355,11 @@ struct p54_tx_data {
u8 align[0];
} __attribute__ ((packed));

+/* unit is ms */
+#define P54_TX_FRAME_LIFETIME 2000
+#define P54_TX_TIMEOUT 4000
+#define P54_STATISTICS_UPDATE 5000
+
#define P54_FILTER_TYPE_NONE 0
#define P54_FILTER_TYPE_STATION BIT(0)
#define P54_FILTER_TYPE_IBSS BIT(1)
diff -Nurp a/drivers/net/wireless/p54/p54.h b/drivers/net/wireless/p54/p54.h
--- a/drivers/net/wireless/p54/p54.h 2008-12-12 23:26:30.000000000 +0100
+++ b/drivers/net/wireless/p54/p54.h 2008-12-13 00:47:20.000000000 +0100
@@ -71,6 +71,7 @@ struct p54_edcf_queue_param {
#define FW_LM20 0x4c4d3230

struct p54_common {
+ struct ieee80211_hw *hw;
u32 rx_start;
u32 rx_end;
struct sk_buff_head tx_queue;
@@ -106,9 +107,7 @@ struct p54_common {
struct ieee80211_tx_queue_stats tx_stats[8];
struct p54_edcf_queue_param qos_params[8];
struct ieee80211_low_level_stats stats;
- struct timer_list stats_timer;
- struct completion stats_comp;
- struct sk_buff *cached_stats;
+ struct delayed_work work;
struct sk_buff *cached_beacon;
int noise;
void *eeprom;