Subject: Re: Network drivers that don't suspend on interface down

From: Matthew Garrett <[email-masked]>
Date: Thu, 21 Dec 2006 03:25:47 +0000

On Wed, Dec 20, 2006 at 10:08:22PM -0500, Daniel Drake wrote:
> Matthew Garrett wrote:
> >Hm. Does the spec not set any upper bound on how long it might take for 
> >APs to respond? I'm afraid that my 802.11 knowledge is pretty slim. 
> 
> I'm not sure, but thats not entirely relevant either.  The time it takes 
> for the AP to respond is not related to the delay between userspace 
> sending the siwscan and giwscan ioctls (unless you're thinking of 
> userspace being too quick, but GIWSCAN already returns -EINPROGRESS when 
> appropriate so this is detectable)

Ah - I've mostly been looking at the ipw* drivers, where giwscan just 
seems to return information cached by the ieee80211 layer. A quick scan 
suggests that most cards behave like this, but prism54 seems to refer to 
the hardware. I can see why that would cause problems.

> I think it's reasonable to keep the interface down, but then when the 
> user does want to connect, bring the interface up, scan, present scan 
> results. Scanning is quick, there would be minimal wait needed here.

Yeah, that's true.

-- 
Matthew Garrett | [email-masked]