Re: RTL8192CU continually reconnecting

[Larry Finger <Larry.Finger@lwfinger.net>]

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On 09/09/2013 05:05 PM, Mark Cave-Ayland wrote:
> On 09/09/13 20:03, Larry Finger wrote:
>
>> There were no secrets in that dump, but it did reveal a major clue.
>>
>> A response from your system for your AP was:
>>
>> mode 2, state 0, is_beacon 0, is_probe_resp 1, length 147
>>
>> For the number of beacons to be updated, the state has to be 2 or 3. My
>> system has scan_ssid=1 in the wpa_supplicant configuration file. When
>> the scan finishes, then a value of 2 is set into the mode variable.
>>
>> The attached updated patch should set the correct mode even if scanning
>> is not enabled.
>
> Aha! This patch is definitely a step in the right direction - with this applied,
> wpa_supplicant now associates immediately with the AP without the initial delay :)
>
> However... I'm still seeing the same "rtlwifi:rtl_watchdog_wq_callback():<0-0>
> AP off, try to reconnect now" message appearing in dmesg after every 10s or so.
> I've uploaded the updated dmesg output to
> http://www.ilande.co.uk/tmp/rtl8192cu_patch-2-dmesg.txt for you to take a look at.
>
> I also tried another experiment which was to change your patch so that instead
> of logging just the first 100 beacons to dmesg, log every 10th beacon (count %
> 10) to dmesg instead. This showed that even when the timeouts are occurring
> against the AP, I'm still seeing a continual stream of beacons from other
> stations on the network.

Looking at only every 10th one could be systematically missing the ones from 
your AP.

> This makes me wonder if Oleksij is correct in that the problem is that not all
> the frames coming from the USB interface are being picked up by the driver.
> Perhaps not all incoming USB RX buffers are being scanned (causing some queued
> frames to be lost) or maybe USB transfers can contain more than 1 frame and
> rtlwifi is only catching the first frame within each notified transfer?

None of those suppositions make any sense.

> To double check whether it was a general ehci-pci problem, I tried plugging in a
> spare zd1211rw dongle and that worked absolutely fine. So I think that's a
> reasonable indication that general USB function is okay.

I do not suspect any USB problem unless it is in rtl8192cu.

Could you please run the attached patch? It will only print messages for your 
AP, and print enough to still be getting them when the AP timeout occurs.

Thanks,

Larry


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Index: wireless-testing-save/drivers/net/wireless/rtlwifi/usb.c
===================================================================
--- wireless-testing-save.orig/drivers/net/wireless/rtlwifi/usb.c
+++ wireless-testing-save/drivers/net/wireless/rtlwifi/usb.c
@@ -484,6 +484,8 @@ static void _rtl_usb_rx_process_agg(stru
 			if (unicast)
 				rtlpriv->link_info.num_rx_inperiod++;
 		}
+		/* static bcn for roaming */
+		rtl_beacon_statistic(hw, skb);
 	}
 }
 
Index: wireless-testing-save/drivers/net/wireless/rtlwifi/core.c
===================================================================
--- wireless-testing-save.orig/drivers/net/wireless/rtlwifi/core.c
+++ wireless-testing-save/drivers/net/wireless/rtlwifi/core.c
@@ -184,6 +184,7 @@ static int rtl_op_add_interface(struct i
 					rtlpriv->cfg->maps
 					[RTL_IBSS_INT_MASKS]);
 		}
+		mac->link_state = MAC80211_LINKED;
 		break;
 	case NL80211_IFTYPE_ADHOC:
 		RT_TRACE(rtlpriv, COMP_MAC80211, DBG_LOUD,
Index: wireless-testing-save/drivers/net/wireless/rtlwifi/base.c
===================================================================
--- wireless-testing-save.orig/drivers/net/wireless/rtlwifi/base.c
+++ wireless-testing-save/drivers/net/wireless/rtlwifi/base.c
@@ -1287,6 +1287,17 @@ void rtl_beacon_statistic(struct ieee802
 {
 	struct rtl_priv *rtlpriv = rtl_priv(hw);
 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
+	static int count;
+
+	/* and only beacons from the associated BSSID, please */
+	if (compare_ether_addr(hdr->addr3, rtlpriv->mac80211.bssid))
+		return;
+
+	if (count++ < 1200) {
+		pr_info("mode %d, state %d, is_beacon %d, is_probe_resp %d, length %d\n",
+			rtlpriv->mac80211.opmode, rtlpriv->mac80211.link_state, ieee80211_is_beacon(hdr->frame_control),
+			ieee80211_is_probe_resp(hdr->frame_control), skb->len);
+	}
 
 	if (rtlpriv->mac80211.opmode != NL80211_IFTYPE_STATION)
 		return;
@@ -1303,10 +1314,6 @@ void rtl_beacon_statistic(struct ieee802
 	if (skb->len <= 40 + FCS_LEN)
 		return;
 
-	/* and only beacons from the associated BSSID, please */
-	if (compare_ether_addr(hdr->addr3, rtlpriv->mac80211.bssid))
-		return;
-
 	rtlpriv->link_info.bcn_rx_inperiod++;
 }
 EXPORT_SYMBOL_GPL(rtl_beacon_statistic);