Re: connman wlan0 scan gets stuck?
On Mon, 2013-01-07 at 13:31 -0800, Stan Hu wrote: connmand[2478]: plugins/wifi.c:wifi_scan_fast() device 0x99048 0x91738 connmand[2478]: plugins/wifi.c:wifi_scan_fast() max ssids 4 The driver on my WiFi device supports only 1 SSID scan. Since connman attempts to feed 2 SSID devices, the failure causes connman to get stuck waiting for a scan to complete. Ok, now I get where this is coming from. wpa_supplicant is/was supposed to handle 4 SSIDs and 16 in later versions, but seems not to cope with that anyway. I'll do a patch and then we'll see if it helps. Cheers, Patrik ___ connman mailing list connman@connman.net http://lists.connman.net/listinfo/connman
Re: connman wlan0 scan gets stuck?
Hi, On Fri, 2013-01-04 at 09:25 -0800, Stan Hu wrote: Let's say you took your device somewhere and connected to SSID Alice. connman saves a settings file in /var/lib/connman for this successful connection. Let's say you then moved your device and connected to SSID Bob. connman also saves another settings file for this connection. Now, when connman starts up, it asks wpa_supplicant to scan SSIDs Alice and Bob and the frequencies on which the device last connected. The SSIDs are scanned only if the WiFi networks were hidden, in other cases a normal broadcast scan is done. Since Alice doesn't exist, the nl80211 driver reports: nl80211: Scan trigger failed: ret=-22 (Invalid argument) Which version of wpa_supplicant is in use? wpa_supplicant never returns a successful scan, so connman gets stuck waiting for the scan to complete. If you call 'iwlist wlan0 scanning', this causes the nl80211 driver to do a full scan WITHOUT the SSIDs. wpa_supplicant returns back the results,connman resumes, and everything works. Can you check ConnMan is stuck by running either 'test/test-connman scan wifi' or 'connmanctl scan wifi'? Both commands wait until the scan is done, which is a few seconds. What about a subsequent scan? If they never return there is a bug somewhere. Cheers, Patrik ___ connman mailing list connman@connman.net http://lists.connman.net/listinfo/connman
Re: connman wlan0 scan gets stuck?
On Mon, Jan 7, 2013 at 12:30 AM, Patrik Flykt patrik.fl...@linux.intel.comwrote: Hi, On Fri, 2013-01-04 at 09:25 -0800, Stan Hu wrote: Let's say you took your device somewhere and connected to SSID Alice. connman saves a settings file in /var/lib/connman for this successful connection. Let's say you then moved your device and connected to SSID Bob. connman also saves another settings file for this connection. Now, when connman starts up, it asks wpa_supplicant to scan SSIDs Alice and Bob and the frequencies on which the device last connected. The SSIDs are scanned only if the WiFi networks were hidden, in other cases a normal broadcast scan is done. connman v1.4 looks like it attempts to scan all the most recent networks that were connected in get_latest_connections() (i.e. profiles that are stored in /var/lib/connman/wifi_*) I think this is true in the latest version of connman as well. Since Alice doesn't exist, the nl80211 driver reports: nl80211: Scan trigger failed: ret=-22 (Invalid argument) Which version of wpa_supplicant is in use? I am using wpa_supplicant v0.73. I think I now fully understand where the -22 invalid argument error is coming from. It appears that the nl80211 scan fails because connman inserts more SSIDs than allowed by the the driver (max_scan_ssids). wpa_supplicant v1.0 added support for the MaxScanSSID parameter. Since v0.73 doesn't support this parameter, this parameter defaults to WPAS_MAX_SCAN_SSIDS (4): connmand[2478]: plugins/wifi.c:wifi_scan_fast() device 0x99048 0x91738 connmand[2478]: plugins/wifi.c:wifi_scan_fast() max ssids 4 The driver on my WiFi device supports only 1 SSID scan. Since connman attempts to feed 2 SSID devices, the failure causes connman to get stuck waiting for a scan to complete. This problem would be cured by upgrading to wpa_supplicant v1.0, but I do think this issue raises a number of questions: 1) Should the WPAS_MAX_SCAN_SSIDS in the supplicant be set to 0 or 1 by default instead of 4? 2) Why doesn't connman time out on the scan after failing to receive a response from wpa_supplicant? 3) wpa_supplicant should send an error message back to connman, which should abort the scan. wpa_supplicant never returns a successful scan, so connman gets stuck waiting for the scan to complete. If you call 'iwlist wlan0 scanning', this causes the nl80211 driver to do a full scan WITHOUT the SSIDs. wpa_supplicant returns back the results,connman resumes, and everything works. Can you check ConnMan is stuck by running either 'test/test-connman scan wifi' or 'connmanctl scan wifi'? Both commands wait until the scan is done, which is a few seconds. What about a subsequent scan? If they never return there is a bug somewhere. I get a dbus error when I attempt to use 'test/test-connman scan wifi'. iwlist is the only thing that kicks it out of the state. Cheers, Patrik ___ connman mailing list connman@connman.net http://lists.connman.net/listinfo/connman ___ connman mailing list connman@connman.net http://lists.connman.net/listinfo/connman
Re: connman wlan0 scan gets stuck?
Ok, I think I figured out the root cause. At a high level, I think this is a bug in the interaction between wpa_supplicant, connman, and the nl80211 driver. Let's say you took your device somewhere and connected to SSID Alice. connman saves a settings file in /var/lib/connman for this successful connection. Let's say you then moved your device and connected to SSID Bob. connman also saves another settings file for this connection. Now, when connman starts up, it asks wpa_supplicant to scan SSIDs Alice and Bob and the frequencies on which the device last connected. Since Alice doesn't exist, the nl80211 driver reports: nl80211: Scan trigger failed: ret=-22 (Invalid argument) wpa_supplicant never returns a successful scan, so connman gets stuck waiting for the scan to complete. If you call 'iwlist wlan0 scanning', this causes the nl80211 driver to do a full scan WITHOUT the SSIDs. wpa_supplicant returns back the results,connman resumes, and everything works. There are several problems I see here: 1) connman should timeout from the failed scan and retry 2) connman should only ask to scan SSIDs if they are present, or not scan explicit SSIDs at all 3) The nl80211 driver should arguably not return an illegal argument error if an SSID does not exist 4) If an error occurs, wpa_supplicant should return either empty scan results or some error message on dbus A quick fix is to erase all cached profiles in /var/lib/connman/wifi* so that connman won't attempt to scan non-existing SSIDs, but I think there should be something in the code to handle cases #1 and #2. On Thu, Jan 3, 2013 at 11:31 PM, Raseel Bhagat raseel.bha...@kpitcummins.com wrote: Hi -Original Message- From: connman-boun...@connman.net [mailto:connman-boun...@connman.net] On Behalf Of Stan Hu Sent: Friday, January 04, 2013 12:09 PM To: connman@connman.net Subject: connman wlan0 scan gets stuck? I'm running connman v1.4 and wpa-supplicant v0.73 (old, I know), but Essentially connmand starts up in a state where no WiFi services are listed unless I either: 1) run 'iwlist scan' 2) clean out the /var/lib/connman/wifi* directory for the AP and restart connman I have been using connman v1.3. However, instead of calling iwlist scan , I do the following after running connmand -n : test-connman enable wifi test-connman scan wifi test-connman services Also, the periodic autoscan by wpa_supplicant seems to be working fine with my setup. Can you try the above and see if you are still facing the issue ? Thanks, Raseel Bhagat ___ connman mailing list connman@connman.net http://lists.connman.net/listinfo/connman ___ connman mailing list connman@connman.net http://lists.connman.net/listinfo/connman
Re: connman wlan0 scan gets stuck?
Hi Stan, On 01/03/2013 10:38 PM, Stan Hu wrote: I'm running connman v1.4 and wpa-supplicant v0.73 (old, I know), but before I try upgrading everything--which is not a trivial matter since the software needs to be deployed on hundreds of devices--I want to understand the issue. Can you scan for the first time? Because I had this problem and I fixed updating wpa_supplicant to 1.0 or grater. Regards, Felipe Tonello ___ connman mailing list connman@connman.net http://lists.connman.net/listinfo/connman
RE: connman wlan0 scan gets stuck?
Hi, I'm running connman v1.4 and wpa-supplicant v0.73 (old, I know), but before I try upgrading everything--which is not a trivial matter since the software needs to be deployed on hundreds of devices--I want to understand the issue. Essentially connmand starts up in a state where no WiFi services are listed unless I either: 1) run 'iwlist scan' 2) clean out the /var/lib/connman/wifi* directory for the AP and restart connman FYI. I saw a similar issue with an old netbook. It's https://bugs.meego.com/show_bug.cgi?id=25307 Bests Jeff ___ connman mailing list connman@connman.net http://lists.connman.net/listinfo/connman
RE: connman wlan0 scan gets stuck?
Hi -Original Message- From: connman-boun...@connman.net [mailto:connman-boun...@connman.net] On Behalf Of Stan Hu Sent: Friday, January 04, 2013 12:09 PM To: connman@connman.net Subject: connman wlan0 scan gets stuck? I'm running connman v1.4 and wpa-supplicant v0.73 (old, I know), but Essentially connmand starts up in a state where no WiFi services are listed unless I either: 1) run 'iwlist scan' 2) clean out the /var/lib/connman/wifi* directory for the AP and restart connman I have been using connman v1.3. However, instead of calling iwlist scan , I do the following after running connmand -n : test-connman enable wifi test-connman scan wifi test-connman services Also, the periodic autoscan by wpa_supplicant seems to be working fine with my setup. Can you try the above and see if you are still facing the issue ? Thanks, Raseel Bhagat ___ connman mailing list connman@connman.net http://lists.connman.net/listinfo/connman
