Re: airo

[Michal Schmidt <mschmidt@redhat.com>]

Dan Williams wrote:
> On Mon, 2007-06-25 at 16:38 +0200, Michal Schmidt wrote:
>> Matteo Croce wrote:
>>> after booting i have this situation:
>>>
>>> root@raver:~# lsmod |fgrep airo
>>> airo                   80016  0
>>> root@raver:~# dmesg |fgrep airo
>>> airo(): Probing for PCI adapters
>>> airo(eth1): cmd:111 status:7f11 rsp0:2 rsp1:0 rsp2:0
>>> airo(eth1): Doing fast bap_reads
>>> airo(eth1): WPA is supported.
>>> airo(eth1): Couldn't register_netdev
>>> airo(): Finished probing for PCI adapters
>>> root@raver:~#
>>>
>>> I have to do this to connect:
>>>
>>> root@raver:~# rmmod airo
>>> root@raver:~# modprobe airo
>>> root@raver:~# dmesg |fgrep airo
>>> airo(): Probing for PCI adapters
>>> airo(eth1): cmd:111 status:7f11 rsp0:2 rsp1:0 rsp2:0
>>> airo(eth1): Doing fast bap_reads
>>> airo(eth1): WPA is supported.
>>> airo(eth1): Couldn't register_netdev
>>> airo(): Finished probing for PCI adapters
>>> airo(): Probing for PCI adapters
>>> airo(eth0): cmd:111 status:7f11 rsp0:2 rsp1:0 rsp2:0
>>> airo(eth0): Doing fast bap_reads
>>> airo(eth0): WPA is supported.
>>> airo(eth0): MAC enabled 0:d:29:4f:c:be
>>> airo(): Finished probing for PCI adapters
>>> root@raver:~#
>>>   
>> Hi Matteo,
>>
>> It looks like some other network interface gets renamed from "eth0" to
>> "eth1" at the same time the airo driver is initializing the card. Does
>> it happen always after booting? Do you have other network interfaces?
>> This patch should fix it. Can you test it?
> 
> Wow, that's somewhat ugly.  Do other drivers just not have this problem,
> or have they worked around it in similar or different ways?  Just trying
> to understand if the scope of the issue is wider than just airo.

For instance, drivers/net/wireless/atmel.c looks very similar, so I
guess it has the same race. With airo the race is just more visible,
because of all the long sleeps it does between getting the name with
dev_alloc_name and finally registering it.

eepro100.c takes rtnl_lock to avoid the issue. So does ns83820.c - it
has a big comment about how ugly it is.

Michal