Re: [Ilw] Re: REGRESSION: v3.2-rcX: iwlagn refuses to associatewith my AP's

From: wwguy
Date: Tue Dec 13 2011 - 13:05:12 EST


Hi Ted,

On Tue, 2011-12-13 at 09:26 -0800, Ted Ts'o wrote:
> On Mon, Dec 12, 2011 at 02:42:53PM -0500, Theodore Ts'o wrote:
> > Hi there,
> >
> > I recently discovered a regression in the iwlagn driver (works in v3.1
> > but not in v3.2-rc2... I'm going to continue to bisect, but I thought
> > I'd give a heads up now). I'm using a Lenovo T410, with the following
> > wireless card:
> >
> > [ 11.197410] iwlwifi 0000:03:00.0: HW Revision ID = 0x35
> > [ 11.197637] iwlwifi 0000:03:00.0: Detected Intel(R) Centrino(R) Advanced-N + WiMAX 6250 AGN, REV=0x84
> >
> > The failure to associate with access points happens at work, with
> > whatever AP's are in use at the Cambridge Google office. When I tried
> > v3.2-rc5 at home, I was able to associate with a consumer-grade NetGear
> > AP, although it was flaky --- that is, it completely failed to associate
> > initially, but then I tried rebooting and I was eventually able to get
> > it to work. At work, I was able to reproduce the problem with a
> > v3.2-rc5 and v3.2-rc2 kernel, but the problem did not manifest itself
> > with a v3.1 kernel.
>
> OK, a follow up. A bisection puts the finger of blame very firmly at:
>
> debcf73 iwlagn: handle GO powersave
>
> Specifically, I can't associate with *any* access points (encrypted or
> not) if I compile a kernel at commit debcf73, but if I compile a
> kernel with its parent (commit 8ad71be), it works fine.
>
> However, as a puzzler, when I tried reverted compiling 3.2-rc5 with
> debcf73 reverted, it did not make the problem go away. So there's
> something debcf73more going on here. I could try doing a bisect with reverts
> of debcf73 at each step, trying to find the problem, but I'm hoping
> this is enough of a hint that someone can tell me either that this is
> fixed already in the linux-wireless tree, or that they know what's
> wrong and can provide a test patch...
>
Thank you for doing all those works,

The "debcf73 iwlagn: handle GO powersave" is part of new WiFi Direct
feature we are introducing for our up-coming new products. As you can
see, the feature still under development and for sure there are a lot
issues we need to flush out and make it perfect.

Here I attach a patch which will disable P2P feature by default, could
you please give it a try, so we know for sure it is something being
introduced by P2P changes.

Of cause, we still need to understand why it is happening and find the
correct solution for it.

Thanks
Wey
>
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