Bug 21962

Summary: iwl3945: 36% packet loss (in an ad-hoc network; ping "suspends" from time to time)
Product: Branch 4.1 Reporter: Ivan Zakharyaschev <imz>
Component: kernel-image-std-defAssignee: Michail Yakushin <silicium>
Status: CLOSED WORKSFORME QA Contact: qa-4.1 <qa-4.1>
Severity: major    
Priority: P3 CC: sem
Version: unspecified   
Hardware: all   
OS: Linux   
Attachments:
Description Flags
/var/log/kernel/info (excerpt) none

Description Ivan Zakharyaschev 2009-10-16 14:18:13 MSD 
Created attachment 3992 [details]
/var/log/kernel/info (excerpt)

2.6.25-std-def-alt8.M41.5
firmware-iwl3945-2.14.1.5-alt1
02:00.0 Network controller: Intel Corporation PRO/Wireless 3945ABG Network Connection (rev 02)

У меня на iwl3945 с одной стороны (и ipw2200 с другой) в ad-hoc сети теряется 36% пакетов (действительно, похоже на "ping замирает периодически" -- https://bugzilla.altlinux.org/show_bug.cgi?id=20360#c1):

[root@localhost ~]# ping dell.local 
PING dell.local (169.254.178.30) 56(84) bytes of data.
64 bytes from dell.local (169.254.178.30): icmp_seq=1 ttl=64 time=7.47 ms
64 bytes from dell.local (169.254.178.30): icmp_seq=2 ttl=64 time=3.38 ms
64 bytes from dell.local (169.254.178.30): icmp_seq=3 ttl=64 time=1.95 ms
64 bytes from dell.local (169.254.178.30): icmp_seq=4 ttl=64 time=3.72 ms
64 bytes from dell.local (169.254.178.30): icmp_seq=5 ttl=64 time=1.98 ms
64 bytes from dell.local (169.254.178.30): icmp_seq=7 ttl=64 time=1.95 ms
64 bytes from dell.local (169.254.178.30): icmp_seq=8 ttl=64 time=1.98 ms
64 bytes from dell.local (169.254.178.30): icmp_seq=15 ttl=64 time=1.69 ms
64 bytes from dell.local (169.254.178.30): icmp_seq=16 ttl=64 time=1.51 ms
64 bytes from dell.local (169.254.178.30): icmp_seq=17 ttl=64 time=1.42 ms
64 bytes from dell.local (169.254.178.30): icmp_seq=18 ttl=64 time=1.51 ms
64 bytes from dell.local (169.254.178.30): icmp_seq=19 ttl=64 time=1.50 ms
64 bytes from dell.local (169.254.178.30): icmp_seq=20 ttl=64 time=1.51 ms
64 bytes from dell.local (169.254.178.30): icmp_seq=22 ttl=64 time=2.85 ms
64 bytes from dell.local (169.254.178.30): icmp_seq=23 ttl=64 time=1.51 ms
64 bytes from dell.local (169.254.178.30): icmp_seq=24 ttl=64 time=1.42 ms
64 bytes from dell.local (169.254.178.30): icmp_seq=25 ttl=64 time=1.21 ms
64 bytes from dell.local (169.254.178.30): icmp_seq=31 ttl=64 time=1.28 ms
64 bytes from dell.local (169.254.178.30): icmp_seq=32 ttl=64 time=2.58 ms
64 bytes from dell.local (169.254.178.30): icmp_seq=33 ttl=64 time=2.56 ms
64 bytes from dell.local (169.254.178.30): icmp_seq=35 ttl=64 time=1.19 ms
64 bytes from dell.local (169.254.178.30): icmp_seq=37 ttl=64 time=1.13 ms
64 bytes from dell.local (169.254.178.30): icmp_seq=38 ttl=64 time=1.13 ms
64 bytes from dell.local (169.254.178.30): icmp_seq=39 ttl=64 time=2.63 ms
64 bytes from dell.local (169.254.178.30): icmp_seq=40 ttl=64 time=2.10 ms
64 bytes from dell.local (169.254.178.30): icmp_seq=41 ttl=64 time=1.12 ms
64 bytes from dell.local (169.254.178.30): icmp_seq=46 ttl=64 time=128 ms
64 bytes from dell.local (169.254.178.30): icmp_seq=47 ttl=64 time=1.04 ms
64 bytes from dell.local (169.254.178.30): icmp_seq=48 ttl=64 time=2.48 ms
64 bytes from dell.local (169.254.178.30): icmp_seq=49 ttl=64 time=2.59 ms
64 bytes from dell.local (169.254.178.30): icmp_seq=51 ttl=64 time=1.03 ms
64 bytes from dell.local (169.254.178.30): icmp_seq=52 ttl=64 time=1.05 ms
64 bytes from dell.local (169.254.178.30): icmp_seq=53 ttl=64 time=1.06 ms
64 bytes from dell.local (169.254.178.30): icmp_seq=55 ttl=64 time=1.12 ms
64 bytes from dell.local (169.254.178.30): icmp_seq=56 ttl=64 time=2.47 ms
64 bytes from dell.local (169.254.178.30): icmp_seq=57 ttl=64 time=0.730 ms
64 bytes from dell.local (169.254.178.30): icmp_seq=58 ttl=64 time=2.10 ms
64 bytes from dell.local (169.254.178.30): icmp_seq=59 ttl=64 time=0.725 ms
64 bytes from dell.local (169.254.178.30): icmp_seq=62 ttl=64 time=0.934 ms
64 bytes from dell.local (169.254.178.30): icmp_seq=63 ttl=64 time=0.732 ms
64 bytes from dell.local (169.254.178.30): icmp_seq=64 ttl=64 time=0.647 ms
64 bytes from dell.local (169.254.178.30): icmp_seq=65 ttl=64 time=0.722 ms
64 bytes from dell.local (169.254.178.30): icmp_seq=66 ttl=64 time=2.12 ms
64 bytes from dell.local (169.254.178.30): icmp_seq=67 ttl=64 time=0.729 ms
64 bytes from dell.local (169.254.178.30): icmp_seq=68 ttl=64 time=0.649 ms
64 bytes from dell.local (169.254.178.30): icmp_seq=69 ttl=64 time=2.16 ms
64 bytes from dell.local (169.254.178.30): icmp_seq=70 ttl=64 time=0.673 ms
64 bytes from dell.local (169.254.178.30): icmp_seq=71 ttl=64 time=0.628 ms
64 bytes from dell.local (169.254.178.30): icmp_seq=72 ttl=64 time=0.654 ms
64 bytes from dell.local (169.254.178.30): icmp_seq=77 ttl=64 time=0.680 ms
64 bytes from dell.local (169.254.178.30): icmp_seq=78 ttl=64 time=0.659 ms
64 bytes from dell.local (169.254.178.30): icmp_seq=80 ttl=64 time=2.09 ms
64 bytes from dell.local (169.254.178.30): icmp_seq=82 ttl=64 time=2.13 ms
64 bytes from dell.local (169.254.178.30): icmp_seq=83 ttl=64 time=0.673 ms
64 bytes from dell.local (169.254.178.30): icmp_seq=84 ttl=64 time=0.664 ms
64 bytes from dell.local (169.254.178.30): icmp_seq=85 ttl=64 time=0.685 ms
64 bytes from dell.local (169.254.178.30): icmp_seq=86 ttl=64 time=2.21 ms
64 bytes from dell.local (169.254.178.30): icmp_seq=92 ttl=64 time=0.712 ms
64 bytes from dell.local (169.254.178.30): icmp_seq=93 ttl=64 time=0.687 ms
^C
--- dell.local ping statistics ---
93 packets transmitted, 59 received, 36% packet loss, time 92285ms
rtt min/avg/max/mdev = 0.628/3.756/128.932/16.472 ms
[root@localhost ~]# 


при этом пишется куча сообщений на стороне iwl3945:

kernel: wlan0: Configured IBSS beacon template
kernel: phy0: Adding new IBSS station ....

(дальше MAC или что-то подобное)

несколько штук в секунду. Я подозреваю, что может быть связь между такой интенсивностью сообщений и тем, что оно нормально не работает.

Сообщения (за час) приложены.

[root@localhost ~]# iwconfig 
lo        no wireless extensions.

yauza     no wireless extensions.

wmaster0  no wireless extensions.

wtibet    IEEE 802.11  ESSID:"tibet"  
          Mode:Ad-Hoc  Frequency:2.412 GHz  Cell: BA:C0:73:88:76:9B   
          Tx-Power=15 dBm   
          Retry min limit:7   RTS thr:off   Fragment thr=2352 B   
          Encryption key:off
          Link Quality:0  Signal level:0  Noise level:0
          Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
          Tx excessive retries:0  Invalid misc:0   Missed beacon:0

[root@localhost ~]# iwlist scan
lo        Interface doesn't support scanning.

yauza     Interface doesn't support scanning.

wmaster0  Interface doesn't support scanning.

wtibet    Interface doesn't support scanning : Resource temporarily unavailable

[root@localhost ~]# 

(Раньше я мог предположить, что это может быть как-то связано и с NetworkManager -- https://bugzilla.altlinux.org/show_bug.cgi?id=18342#c3 , но теперь NetworkManager я удалил; ещё я видел сходства с https://bugzilla.altlinux.org/show_bug.cgi?id=20360 " слишком много сообщений в syslog", но там всё же другая проблема, как видно.)
Comment 1 Ivan Zakharyaschev 2009-10-16 15:09:25 MSD 
This problem is not present in 2.6.30-std-def-alt14 from Sisyphus.
Comment 2 Mikhail Efremov 2009-10-19 01:43:07 MSD 
С #18342 у меня было подозрение, что проблема в периодическом сканировании, которое инициирует NM, но раз проблема сохраняется и без NM, то дело видимо не в этом. Проблема с #18342 исчезла с обновлением ядра, насколько я понимаю. Видимо проблема в драйвере.
Comment 3 Michail Yakushin 2010-07-06 10:51:59 MSD 
Проверьте на современных бранчах.