Some buggy APs do not respond to unicast probe requests or send unicast probe requests very delayed so in the worst case we should try to send broadcast probe requests, otherwise we can get disconnected from these APs. Even if drivers do not have filters to disregard probe responses from foreign APs mac80211 will only process probe responses from our associated AP for re-arming connection monitoring. We need to do this since the beacon monitor does not push back the connection monitor by design so even if we are getting beacons from these type of APs our connection monitor currently relies heavily on the way the probe requests are received on the AP. An example of an AP affected by this is the Nexus One, but this has also been observed with random APs. We can probably optimize this later by using null funcs instead of probe requests. For more details refer to: http://code.google.com/p/chromium-os/issues/detail?id=5715 This patch has fixes for stable kernels [2.6.35+] Cc: stable@xxxxxxxxxx Cc: Paul Stewart <pstew@xxxxxxxxxx> Cc: Amod Bodas <amod.bodas@xxxxxxxxxxx> Signed-off-by: Luis R. Rodriguez <lrodriguez@xxxxxxxxxxx> --- net/mac80211/mlme.c | 13 +++++++++++-- 1 files changed, 11 insertions(+), 2 deletions(-) diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c index c2e1838..816566b 100644 --- a/net/mac80211/mlme.c +++ b/net/mac80211/mlme.c @@ -1038,10 +1038,19 @@ static void ieee80211_mgd_probe_ap_send(struct ieee80211_sub_if_data *sdata) { struct ieee80211_if_managed *ifmgd = &sdata->u.mgd; const u8 *ssid; + u8 *dst = ifmgd->associated->bssid; + u8 unicast_limit = max(1, IEEE80211_MAX_PROBE_TRIES - 3); + + /* + * Try sending broadcast probe requests for the last three + * probe requests after the first ones failed since some + * buggy APs only support broadcast probe requests. + */ + if (ifmgd->probe_send_count >= unicast_limit) + dst = NULL; ssid = ieee80211_bss_get_ie(ifmgd->associated, WLAN_EID_SSID); - ieee80211_send_probe_req(sdata, ifmgd->associated->bssid, - ssid + 2, ssid[1], NULL, 0); + ieee80211_send_probe_req(sdata, dst, ssid + 2, ssid[1], NULL, 0); ifmgd->probe_send_count++; ifmgd->probe_timeout = jiffies + IEEE80211_PROBE_WAIT; -- 1.7.0.4 -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
