On Fri, 2009-07-31 at 09:43 +0200, Johannes Berg wrote:
> On Fri, 2009-07-31 at 10:08 +0300, Maxim Levitsky wrote:
> > On Wed, 2009-07-29 at 14:32 -0700, Reinette Chatre wrote:
> > > From: Reinette Chatre <reinette.chatre@xxxxxxxxx>
> > >
> > > The connection monitor currently relies on probe requests paired
> > > with probe responses to ensure that a connection is alive. This is
> > > fragile in some environments where probe responses can get lost.
> > > When we receive beacons we can also consider the connection to be
> > > alive, so cancel connection poll instance when we receive a beacon.
> > >
> > > The debug message "cancelling probereq poll due to a received beacon"
> > > is removed as part of this change as this case is hit very often after
> > > the above change and debug log receives significant number of these messages.
> >
> > In my opinion this is the correct solution
> > I did plenty of wireless monitoring, and I see that nobody sends probe
> > requests at that rate (1 per second it seems). This is ridiculous.
>
> Fix it then. Offer an implementation of your superior solution. We've
> done pretty much exactly what you're all pointing out _forever_ in
> mac80211, ever since it was initially merged. Now that it's more
> explicit in the code, people are complaining?
>
> johannes
Here it is:
First patch makes the probe requests be retried (and with it and only
it, my connection is very stable, it never retries more that 3 times,
and I set max retries to 5)
Second patch, trivial one bumps up the timeouts (30 for ping, and 1/2
for response, so device won't send out frames too often)
I attach the patches, since I afraid my mailer would mangle them.
Here they are in-line too:
-------------------------------------------------------------------------------------------------
[MAC80211] Retry probe request few times, before assuming that AP is out of range
From: Maxim Levitsky <maximlevitsky@xxxxxxxxx>
Fixes very often reconnects while connected to nearby APs
Signed-off-by: Maxim Levitky <maximlevitsky@xxxxxxxxx>
---
net/mac80211/ieee80211_i.h | 1 +
net/mac80211/mlme.c | 27 ++++++++++++++++++++++++---
2 files changed, 25 insertions(+), 3 deletions(-)
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index aec6853..ac2489b 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -280,6 +280,7 @@ struct ieee80211_if_managed {
struct work_struct beacon_loss_work;
unsigned long probe_timeout;
+ unsigned long probe_miss_count;
struct mutex mtx;
struct ieee80211_bss *associated;
diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index ee83125..38ef7f2 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -31,6 +31,7 @@
#define IEEE80211_AUTH_MAX_TRIES 3
#define IEEE80211_ASSOC_TIMEOUT (HZ / 5)
#define IEEE80211_ASSOC_MAX_TRIES 3
+#define IEEE80211_ASSOC_RETRIES 5
/*
* beacon loss detection timeout
@@ -1209,6 +1210,7 @@ static void ieee80211_mgd_probe_ap(struct ieee80211_sub_if_data *sdata,
ieee80211_recalc_ps(sdata->local, -1);
mutex_unlock(&sdata->local->iflist_mtx);
+ sdata->u.mgd.probe_miss_count = 0;
ssid = ieee80211_bss_get_ie(&ifmgd->associated->cbss, WLAN_EID_SSID);
ieee80211_send_probe_req(sdata, ifmgd->associated->cbss.bssid,
ssid + 2, ssid[1], NULL, 0);
@@ -2072,17 +2074,36 @@ static void ieee80211_sta_work(struct work_struct *work)
if (ifmgd->flags & (IEEE80211_STA_BEACON_POLL |
IEEE80211_STA_CONNECTION_POLL) &&
ifmgd->associated) {
+
+ u8 bssid[ETH_ALEN];
+ const u8 *ssid;
+
+ memcpy(bssid, ifmgd->associated->cbss.bssid, ETH_ALEN);
+
if (time_is_after_jiffies(ifmgd->probe_timeout))
run_again(ifmgd, ifmgd->probe_timeout);
- else {
- u8 bssid[ETH_ALEN];
+
+ else if (ifmgd->probe_miss_count < IEEE80211_ASSOC_RETRIES) {
+
+ printk(KERN_DEBUG "No probe response from AP %pM"
+ " after %dms, try %d\n", bssid,
+ (1000 * IEEE80211_PROBE_WAIT)/HZ,
+ (int)ifmgd->probe_miss_count);
+
+ ifmgd->probe_miss_count++;
+ ifmgd->probe_timeout = jiffies + IEEE80211_PROBE_WAIT;
+ run_again(ifmgd, ifmgd->probe_timeout);
+
+ ssid = ieee80211_bss_get_ie(&ifmgd->associated->cbss, WLAN_EID_SSID);
+ ieee80211_send_probe_req(sdata, ifmgd->associated->cbss.bssid,
+ ssid + 2, ssid[1], NULL, 0);
+ } else {
/*
* We actually lost the connection ... or did we?
* Let's make sure!
*/
ifmgd->flags &= ~(IEEE80211_STA_CONNECTION_POLL |
IEEE80211_STA_BEACON_POLL);
- memcpy(bssid, ifmgd->associated->cbss.bssid, ETH_ALEN);
printk(KERN_DEBUG "No probe response from AP %pM"
" after %dms, disconnecting.\n",
bssid, (1000 * IEEE80211_PROBE_WAIT)/HZ);
------------------------------------------------------------------------------------------
[MAC80211] Increase timeouts for AP polling
From: Maxim Levitsky <maximlevitsky@xxxxxxxxx>
Do a poll every 30 seconds, and wait for response half a second
Signed-off-by: Maxim Levitsky <maximlevitsky@xxxxxxxxx>
---
net/mac80211/mlme.c | 4 ++--
1 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index 38ef7f2..a8ab40c 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -42,13 +42,13 @@
* Time the connection can be idle before we probe
* it to see if we can still talk to the AP.
*/
-#define IEEE80211_CONNECTION_IDLE_TIME (2 * HZ)
+#define IEEE80211_CONNECTION_IDLE_TIME (30 * HZ)
/*
* Time we wait for a probe response after sending
* a probe request because of beacon loss or for
* checking the connection still works.
*/
-#define IEEE80211_PROBE_WAIT (HZ / 5)
+#define IEEE80211_PROBE_WAIT (HZ / 2)
#define TMR_RUNNING_TIMER 0
#define TMR_RUNNING_CHANSW 1
[MAC80211] Retry probe request few times, before assuming that AP is out of range
From: Maxim Levitsky <maximlevitsky@xxxxxxxxx>
Fixes very often reconnects while connected to nearby APs
Signed-off-by: Maxim Levitky <maximlevitsky@xxxxxxxxx>
---
net/mac80211/ieee80211_i.h | 1 +
net/mac80211/mlme.c | 27 ++++++++++++++++++++++++---
2 files changed, 25 insertions(+), 3 deletions(-)
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index aec6853..ac2489b 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -280,6 +280,7 @@ struct ieee80211_if_managed {
struct work_struct beacon_loss_work;
unsigned long probe_timeout;
+ unsigned long probe_miss_count;
struct mutex mtx;
struct ieee80211_bss *associated;
diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index ee83125..38ef7f2 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -31,6 +31,7 @@
#define IEEE80211_AUTH_MAX_TRIES 3
#define IEEE80211_ASSOC_TIMEOUT (HZ / 5)
#define IEEE80211_ASSOC_MAX_TRIES 3
+#define IEEE80211_ASSOC_RETRIES 5
/*
* beacon loss detection timeout
@@ -1209,6 +1210,7 @@ static void ieee80211_mgd_probe_ap(struct ieee80211_sub_if_data *sdata,
ieee80211_recalc_ps(sdata->local, -1);
mutex_unlock(&sdata->local->iflist_mtx);
+ sdata->u.mgd.probe_miss_count = 0;
ssid = ieee80211_bss_get_ie(&ifmgd->associated->cbss, WLAN_EID_SSID);
ieee80211_send_probe_req(sdata, ifmgd->associated->cbss.bssid,
ssid + 2, ssid[1], NULL, 0);
@@ -2072,17 +2074,36 @@ static void ieee80211_sta_work(struct work_struct *work)
if (ifmgd->flags & (IEEE80211_STA_BEACON_POLL |
IEEE80211_STA_CONNECTION_POLL) &&
ifmgd->associated) {
+
+ u8 bssid[ETH_ALEN];
+ const u8 *ssid;
+
+ memcpy(bssid, ifmgd->associated->cbss.bssid, ETH_ALEN);
+
if (time_is_after_jiffies(ifmgd->probe_timeout))
run_again(ifmgd, ifmgd->probe_timeout);
- else {
- u8 bssid[ETH_ALEN];
+
+ else if (ifmgd->probe_miss_count < IEEE80211_ASSOC_RETRIES) {
+
+ printk(KERN_DEBUG "No probe response from AP %pM"
+ " after %dms, try %d\n", bssid,
+ (1000 * IEEE80211_PROBE_WAIT)/HZ,
+ (int)ifmgd->probe_miss_count);
+
+ ifmgd->probe_miss_count++;
+ ifmgd->probe_timeout = jiffies + IEEE80211_PROBE_WAIT;
+ run_again(ifmgd, ifmgd->probe_timeout);
+
+ ssid = ieee80211_bss_get_ie(&ifmgd->associated->cbss, WLAN_EID_SSID);
+ ieee80211_send_probe_req(sdata, ifmgd->associated->cbss.bssid,
+ ssid + 2, ssid[1], NULL, 0);
+ } else {
/*
* We actually lost the connection ... or did we?
* Let's make sure!
*/
ifmgd->flags &= ~(IEEE80211_STA_CONNECTION_POLL |
IEEE80211_STA_BEACON_POLL);
- memcpy(bssid, ifmgd->associated->cbss.bssid, ETH_ALEN);
printk(KERN_DEBUG "No probe response from AP %pM"
" after %dms, disconnecting.\n",
bssid, (1000 * IEEE80211_PROBE_WAIT)/HZ);
[MAC80211] Increase timeouts for AP polling
From: Maxim Levitsky <maximlevitsky@xxxxxxxxx>
Do a poll every 30 seconds, and wait for response half a second
Signed-off-by: Maxim Levitsky <maximlevitsky@xxxxxxxxx>
---
net/mac80211/mlme.c | 4 ++--
1 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index 38ef7f2..a8ab40c 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -42,13 +42,13 @@
* Time the connection can be idle before we probe
* it to see if we can still talk to the AP.
*/
-#define IEEE80211_CONNECTION_IDLE_TIME (2 * HZ)
+#define IEEE80211_CONNECTION_IDLE_TIME (30 * HZ)
/*
* Time we wait for a probe response after sending
* a probe request because of beacon loss or for
* checking the connection still works.
*/
-#define IEEE80211_PROBE_WAIT (HZ / 5)
+#define IEEE80211_PROBE_WAIT (HZ / 2)
#define TMR_RUNNING_TIMER 0
#define TMR_RUNNING_CHANSW 1
