[PATCH] ipw2200: batch non-user-requested scan result notifications
ipw2200 makes extensive use of background scanning when unassociated or
down. Unfortunately, the firmware sends scan completed events many
times per second, which the driver pushes directly up to userspace.
This needlessly wakes up processes listening for wireless events many
times per second. Batch together scan completed events for
non-user-requested scans and send them up to userspace every 4 seconds.
Scan completed events resulting from an SIOCSIWSCAN call are pushed up
without delay.
Signed-off-by: Dan Williams <dcbw@redhat.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/ipw2200.c b/drivers/net/wireless/ipw2200.c
index 2119a79..feb8fcb 100644
--- a/drivers/net/wireless/ipw2200.c
+++ b/drivers/net/wireless/ipw2200.c
@@ -1740,8 +1740,10 @@
if (disable_radio) {
priv->status |= STATUS_RF_KILL_SW;
- if (priv->workqueue)
+ if (priv->workqueue) {
cancel_delayed_work(&priv->request_scan);
+ cancel_delayed_work(&priv->scan_event);
+ }
queue_work(priv->workqueue, &priv->down);
} else {
priv->status &= ~STATUS_RF_KILL_SW;
@@ -1992,6 +1994,7 @@
wake_up_interruptible(&priv->wait_command_queue);
priv->status &= ~(STATUS_ASSOCIATED | STATUS_ASSOCIATING);
cancel_delayed_work(&priv->request_scan);
+ cancel_delayed_work(&priv->scan_event);
schedule_work(&priv->link_down);
queue_delayed_work(priv->workqueue, &priv->rf_kill, 2 * HZ);
handled |= IPW_INTA_BIT_RF_KILL_DONE;
@@ -4343,6 +4346,37 @@
IPW_DEBUG_NOTIF("Missed beacon: %d\n", missed_count);
}
+static void ipw_scan_event(struct work_struct *work)
+{
+ union iwreq_data wrqu;
+
+ struct ipw_priv *priv =
+ container_of(work, struct ipw_priv, scan_event.work);
+
+ wrqu.data.length = 0;
+ wrqu.data.flags = 0;
+ wireless_send_event(priv->net_dev, SIOCGIWSCAN, &wrqu, NULL);
+}
+
+static void handle_scan_event(struct ipw_priv *priv)
+{
+ /* Only userspace-requested scan completion events go out immediately */
+ if (!priv->user_requested_scan) {
+ if (!delayed_work_pending(&priv->scan_event))
+ queue_delayed_work(priv->workqueue, &priv->scan_event,
+ round_jiffies(msecs_to_jiffies(4000)));
+ } else {
+ union iwreq_data wrqu;
+
+ priv->user_requested_scan = 0;
+ cancel_delayed_work(&priv->scan_event);
+
+ wrqu.data.length = 0;
+ wrqu.data.flags = 0;
+ wireless_send_event(priv->net_dev, SIOCGIWSCAN, &wrqu, NULL);
+ }
+}
+
/**
* Handle host notification packet.
* Called from interrupt routine
@@ -4705,14 +4739,8 @@
* on how the scan was initiated. User space can just
* sync on periodic scan to get fresh data...
* Jean II */
- if (x->status == SCAN_COMPLETED_STATUS_COMPLETE) {
- union iwreq_data wrqu;
-
- wrqu.data.length = 0;
- wrqu.data.flags = 0;
- wireless_send_event(priv->net_dev, SIOCGIWSCAN,
- &wrqu, NULL);
- }
+ if (x->status == SCAN_COMPLETED_STATUS_COMPLETE)
+ handle_scan_event(priv);
break;
}
@@ -9490,6 +9518,10 @@
struct ipw_priv *priv = ieee80211_priv(dev);
struct iw_scan_req *req = (struct iw_scan_req *)extra;
+ mutex_lock(&priv->mutex);
+ priv->user_requested_scan = 1;
+ mutex_unlock(&priv->mutex);
+
if (wrqu->data.length == sizeof(struct iw_scan_req)) {
if (wrqu->data.flags & IW_SCAN_THIS_ESSID) {
ipw_request_direct_scan(priv, req->essid,
@@ -10668,6 +10700,7 @@
}
cancel_delayed_work(&priv->request_scan);
+ cancel_delayed_work(&priv->scan_event);
ipw_reset_stats(priv);
/* Ensure the rate is updated immediately */
priv->last_rate = ipw_get_current_rate(priv);
@@ -10705,7 +10738,8 @@
if (!(priv->status & STATUS_EXIT_PENDING)) {
/* Queue up another scan... */
queue_delayed_work(priv->workqueue, &priv->request_scan, 0);
- }
+ } else
+ cancel_delayed_work(&priv->scan_event);
}
static void ipw_bg_link_down(struct work_struct *work)
@@ -10735,6 +10769,7 @@
INIT_WORK(&priv->up, ipw_bg_up);
INIT_WORK(&priv->down, ipw_bg_down);
INIT_DELAYED_WORK(&priv->request_scan, ipw_request_scan);
+ INIT_DELAYED_WORK(&priv->scan_event, ipw_scan_event);
INIT_WORK(&priv->request_passive_scan, ipw_request_passive_scan);
INIT_DELAYED_WORK(&priv->gather_stats, ipw_bg_gather_stats);
INIT_WORK(&priv->abort_scan, ipw_bg_abort_scan);
@@ -11766,6 +11801,7 @@
cancel_delayed_work(&priv->adhoc_check);
cancel_delayed_work(&priv->gather_stats);
cancel_delayed_work(&priv->request_scan);
+ cancel_delayed_work(&priv->scan_event);
cancel_delayed_work(&priv->rf_kill);
cancel_delayed_work(&priv->scan_check);
destroy_workqueue(priv->workqueue);