Re: iwlagn: associating with AP causes kernel hiccup

From: Tomas Winkler
Date: Sun Oct 19 2008 - 19:12:25 EST


On Mon, Oct 20, 2008 at 12:52 AM, Andrew Lutomirski <luto@xxxxxxxxxxxxx> wrote:
> On Sun, Oct 19, 2008 at 6:12 PM, Tomas Winkler <tomasw@xxxxxxxxx> wrote:
>> On Sun, Oct 19, 2008 at 5:18 PM, Andy Lutomirski <luto@xxxxxxxxxxxxx> wrote:
>>> Richard Scherping wrote:
>>>>
>>>> Tomas Winkler schrieb:
>>
>>>
>>> Amen.
>> Stable doesn't mean all components are stable, citation from Linus blog:
>> "It doesn't have to be perfect (and obviously no release ever is), but
>> it needs to be in reasonable shape"
>>
>> The fact is that some critical patches were rejected as not
>> regressions in rc cycle and probably need to be pushed to the stable
>> version now or distribution will merge them.
>> We gave more priority for testing 32 bit version so it is more stable
>> then 64 bit which got much less in house testing and we've missed many
>> issues there. The driver doesn't get full exposure till it's get to
>> the public in stable version therefore no bugs are opened in the rc
>> cycle so also are not fixed in the stable version. and unfortunately
>> there is no much system testing at all for what get's into merging
>> window.
>> Second the whole mac80211 stack didn't address fully MQ rewrite so
>> it's a bit shaky as well and this will be fact also in 2.6.28.
>
> OK.
>
>>
>> This driver has been available and more-or-less working for ages.
>>> What kernel am I supposed to run if I just want a stable system? Haven't
>>> found one yet, other than distro kernels...
>>>
>>> In any case, I've seen these complete system hiccups with iwl4965 and iwlagn
>>> since at least 2.6.25 and through quite a few wireless-testing versions. I
>>> bet that this, along with things like it, is the culprit:
>>
>> Haven't seen you've filled bug for it.
>
> Fair enough. #1790.
>
Appreciated.

>>
>> Locking need to be really revised but till now I didn't see show
>> stoppers issues so it didn't get priority
>>
>>> Would I be out of line for wishing the iwlwifi developers
>> Patches are always welcome
>
> I can write a patch to add a mutex and change it to:
>
> take mutex
> grab_nic
> spinlock
>
> but I bet that would break all kinds of things. :)
>
I'm far from being lock master but I think mutex just won't work here
it can be used only in sleep-able context Also if I'm not mistake if
you using the lock in irq context we must use irqsafe version of the
spin lock,
Thanks
Tomas
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