OOPS in airo driver, 2.4 serial, skbuff.c: 315

OOPS in airo driver, 2.4 serial, skbuff.c: 315

[Christopher Curtis]

Marc Giger wrote:
> On Fri, 04 Apr 2003 17:47:55 -0500
> Christopher Curtis <chris.curtis@riptidesoftware.com> wrote:
>> > I use a cisco pcmcia aironet card.
>> > kernel: kernel BUG at skbuff.c:315!
>>
>>I have the same problem with 2.4.21-pre5; do you know of a patch?
> 
> Yep, look @ http://cvs.sourceforge.net/cgi-bin/viewcvs.cgi/airo-linux/airo-linux/kernel/
> This driver is fixed but I still have the same problem...it just takes a little more time until it shows up...
> IMPORTANT: Please report bugs to Javier Achirica <achirica@telefonica.net> AND to the lkml linux-kernel@vger.kernel.org!

Hello all,

I had been running a 2.4.19 kernel with the same configuration without 
any problems.  I was told that I had to cut the TxPower from 100mW to 
20mW and found that this could only be done in the prepatches for the 
2.4.x series, so I upgraded to the latest 2.4.21-pre5 kernel.  I had 
been using the card without any problems using apt-get.  Then I tried 
connecting to the machine using VNC.  The system would OOPS in under a 
minute, regularly and repeatedly.

This morning I came in regretting not only the time change, but the 
possibility that I'd have to spend the next few days bug hunting. 
However, it appears that there may be a 'tell': aux_bap.  Normally, the 
only airo.o option I specified was the SSID, which defaulted the aux_bap 
setting to 0.  I set this value to 1, disabled my firewall settings, and 
ran VNC again.  No crashes.  I re-enabled the firewall and let it run. 
No crashes.  It ran fine for about 1/2 hr.

I then removed the aux_bap parameter, reloaded the driver, and tried to 
test some more.  Within 10 seconds, before VNC had painted the full 
screen, I got:

airo: BAP error 4000 2ocal Loopback
Warning kfree_skb passed an skb still on a list (from d0ae27dc)
kernel BUG at skbuff.c:315!
invalid operand: 0000
...
and a bunch of other things I can't ksymoops.

I think the "ocal Loopback" is cruft from a previous ifconfig.  However, 
it may be important to note that I was doing an ifconfig when this 
happened (probably not).  FWIW: eth0 (onboard) printed fine, as did eth1 
(the airo), then the 'lo' was overwritten by the OOPS.

I hope this is helpful to someone,
Chris

OOPS in airo.c [kernel BUG at skbuff.c:315!] 2.4 series

[Christopher Curtis]

Hello again,

>>>Yep, look @ http://cvs.sourceforge.net/cgi-bin/viewcvs.cgi/airo-linux/airo-linux/kernel/

I've now installed this driver and it has had no effect.  VNC still 
causes this lockup readily.  The symptoms are the same: alt-sysrq works, 
but the keyboard is frozen.  I can sync disks, but I can't reboot.

Hopefully this report will be better than the last; I'm running vanilla 
kernel 2.4.21-pre5 with the 'badram', 'debianlogo', 'lowlatency', and 
'preempt' patches.  My previous report of apparent success with the 
aux_bap=1 setting was flawed.  It failed as well.

The OOPS generally looks like this:
airo: BAP error 4000 2
Warning: kfree_skb passed an skb still on a list (from d0acb466)
kernel BUG at skbuff.c:315!
invalid operand: 0000
[...]
Call Trace:    [<d0acb466>] [<d0acb466>] [<c011d117>] [<c0105550>]

rebooting and running 'ksyms' for each of these gives:

d0ac8060: __insmod_airo_S.text_L43104
d0acb466
d0acba20: stop_airo_card

but nothing for the c0* addresses.  Further info is that I am using a 
Cisco 350 PCMCIA (PC-104/ISA) wireless card with the TxPower set to 20mW 
(14dB) and no encryption; running in managed mode.

I am also now subscribed to the LKML so I can see replies.  I've been 
told that the 2.4.19 driver works with 2.4.20 so I may try that next. 
That or the Cisco driver ...

Thanks for any help, and please Cc: me directly.
Christopher

Re: OOPS in airo.c [kernel BUG at skbuff.c:315!] 2.4 series

[Javier Achirica]

Hello,

Can you give a try at the latest version of the code at the CVS? Looks
like it solves the problem for at least some users. If it's at least an
improvement, I'd like to commit it to the kernel source for 2.4.21.

Thanks,
Javier Achirica