Bug 1822 - Call trace at mac80211.h:1884
: Call trace at mac80211.h:1884
Status: VERIFIED TESTED_PATCH_EXISTS
: iwlwifi
BSS
: unspecified
: All Cards Fedora Core 9
: P1 critical
Assigned To:
:
:
:
:
:
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Reported: 2008-11-11 00:53 by
Modified: 2009-01-20 21:04 (History)


Attachments
Call trace (6.55 KB, text/plain)
2008-11-11 00:53, Jeff Zheng
Details
dmesg with debug50=0x43fff (39.90 KB, text/plain)
2008-11-11 22:24, Jeff Zheng
Details
fix warn on rs (1.71 KB, patch)
2008-12-22 21:42, Mohamed Abbas
Details | Diff


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Description From 2008-11-11 00:53:01
Created an attachment (id=1664) [details]
Call trace

Testing Environment
Platform        :       Intel SDV M3M41
Wireless Card   :       Intel(R) WiFi Link 5100
OS              :       Redhat Fedora 9 64bit
AP              :       Cisco 1250
uCode           :       iwlwifi-5000-1.ucode 7.A.1.1B
Source          :       official linux kernel 2.6.28-rc2

Issue:
After DUT associates to AP, switch to another AP will get call trace at
mac80211.h:1884. dmesg log attached. It's easy to reproduce this issue. Since
it's official kernel, I don't think it's proper to see call trace many times.

Steps to Reproduce:
 1 modprobe iwlagn
 2 ifconfig wlan0 up
 3 iwconfig wlan0 channel 8 essid <essid1>
 4 iwconfig to check if already associated to <essid1>
 5 iwconfig wlan0 channel 149 essid <essid2>
 6 dmesg will show calltrace attached.
------- Comment #1 From 2008-11-11 16:12:37 -------
Please try with the development tree.
------- Comment #2 From 2008-11-11 22:24:45 -------
Created an attachment (id=1671) [details]
dmesg with debug50=0x43fff
------- Comment #3 From 2008-11-11 22:28:20 -------
Same on development tree with commit 957b2e1c1aca34e1ad1999d1a215db69a70f695f
(Nov. 7)
------- Comment #4 From 2008-12-08 23:57:07 -------
This issue has been fixed in development tree. Since this issue original found
in official kernel, we will check if this issue is fixed in official kernel.
------- Comment #5 From 2008-12-22 07:58:31 -------
*** Bug 1865 has been marked as a duplicate of this bug. ***
------- Comment #6 From 2008-12-22 08:00:19 -------
This issue also happens on 4965. Following script always reproduced this call
trace on our machines.

#!/bin/bash
set -x
modprobe -r iwlagn ;sleep 1
modprobe iwlagn debug=0x43fff;sleep 1
iwconfig wlan0 essid otc-11215947-dlink2-g channel 11 ;sleep 2
ifconfig wlan0 192.168.50.191 ;sleep 1
ping -c 3 192.168.50.75 ;sleep 1
iwconfig wlan0 channel 149 essid otc-11215947-dlink2-a;sleep 1
dmesg
------- Comment #7 From 2008-12-22 08:03:04 -------
Change the severity since this issue is top 10 of kerneloops.org. This issue
happened on both official kernel and iwlwifi-2.6
------- Comment #8 From 2008-12-22 21:42:43 -------
Created an attachment (id=1759) [details]
fix warn on rs

fix call trace at mac80211.h
------- Comment #9 From 2008-12-22 21:43:29 -------
please try out against latest
------- Comment #10 From 2009-01-06 08:23:04 -------

(In reply to comment #8)
> Created an attachment (id=1759) [details] [details]
> fix warn on rs
> 
> fix call trace at mac80211.h
> 

(In reply to comment #9)
> please try out against latest
> 


Are there any results available from testing this patch? This is a high profile
issue and if this patch solves the problem we should get it upstream.
------- Comment #11 From 2009-01-06 16:00:01 -------
*** Bug 1862 has been marked as a duplicate of this bug. ***
------- Comment #12 From 2009-01-06 18:15:05 -------
I didn't see this call trace in recent testing. And I tried the script in
comment #4 for more than 30 times without see the call trace. So close this bug
(though it's originally in official kernel). I'll reopen it if I see it again
in the future.
------- Comment #13 From 2009-01-07 08:28:01 -------
(In reply to comment #12)
> I didn't see this call trace in recent testing. And I tried the script in
> comment #4 for more than 30 times without see the call trace. So close this bug
> (though it's originally in official kernel). I'll reopen it if I see it again
> in the future.
> 

Did your testing use the patch from comment #8 ?
------- Comment #14 From 2009-01-07 17:49:51 -------
No, I didn't apply that patch.
------- Comment #15 From 2009-01-08 08:44:53 -------
Mohamed,

Do you perhaps know why the problem disappeared without applying your patch? Do
you still want your patch included upstream?
------- Comment #16 From 2009-01-08 10:04:12 -------
I will look at mac80211 I see if they did anything to fix. I will get back to
you if this patch still needed.
------- Comment #17 From 2009-01-08 15:11:05 -------
I still see this problem with latest tree. make sure first you associate with G
AP then you switch to A network like doing #iwconfig wlan0 channel 149 essid
<essid2>
you will see the assert.
------- Comment #18 From 2009-01-08 17:59:13 -------
Yes. I saw it again with the latest code (commit
8e26739cd40a0e9772ec3ccc11f60fd5275cf0ae). Very weired. I tried it for a long
time on Tuesday since this was reported by me...

I will apply Mohamed's patch and test again...
------- Comment #19 From 2009-01-08 18:14:23 -------
Yes. After applying Mohamed's patch, I don't see the call trace again. I tried
on both 32/64bit OS on 4965 machines.
------- Comment #20 From 2009-01-09 08:46:42 -------
(In reply to comment #19)
> Yes. After applying Mohamed's patch, I don't see the call trace again. I tried
> on both 32/64bit OS on 4965 machines.
> 

Jeff, thank you very much for testing.

Mohamed, could you please send me the patch with a descriptive commit message
and Signed-off-by ? 
------- Comment #21 From 2009-01-15 22:13:31 -------
This issue exists on 3945/4965/5300 for official 2.6.28 kernel
------- Comment #22 From 2009-01-20 18:34:33 -------
Still exists in 2.6.29-rc1
------- Comment #23 From 2009-01-20 20:18:41 -------
Mohamed's patch as integrated into Fedora's kernel-2.6.28.1-9.rc2.fc10.x86_64
fixes the problem for me.  No more oopses or disconnects.
------- Comment #24 From 2009-01-20 21:04:19 -------
(In reply to comment #22)
> Still exists in 2.6.29-rc1
> 

The patch has not been included in the vanilla 2.6.29-rcX kernel yet.