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Subject: Re: [PATCH v8 2/2] mac80211:  Support ht-cap over-rides.
From: Johannes Berg <johannes@sipsolutions.net>
To: Ben Greear <greearb@candelatech.com>
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Date: Wed, 09 Nov 2011 09:37:12 +0100
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On Tue, 2011-11-08 at 15:11 -0800, Ben Greear wrote:

> > Please. I'd rather go over a bit than read the above :-)
> 
> I just fixed this by using a tmp variable.  Hopefully the
> compiler is smart enough to make it disappear.

That works, yeah.

> > I really think that'd be much nicer. As it is now we have to add all
> > these checks everywhere, if we just calculate it once and then change
> > places to use it we just have to remember to use the right thing.
> 
> I'm quite nervous about attempting this change.  I'm pretty
> confident my current patch works as designed, and over all,
> it's pretty non-intrusive.  I am afraid that if I start trying
> to substitute something for sband->ht_cap that I'm going
> to end up changing a lot of code and possibly adding all sorts
> of strange bugs.

You should only have to change the places where you now added the
overrides, no?

> Out of curiousity, if one is doing off-channel work, wouldn't
> sband be different from when we associated and possibly different
> in it's ht-capabilities?  If so, the used-ht-caps would not
> be valid for that work?

Well the off-channel work will be on the channel that you're going to be
using after a successful connection, so that should be OK.

I'd at least like to try. If it ends up a disaster maybe we shouldn't,
but the way you go back to the mask & set all the time makes me a bit
nervous.

johannes