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

From: Matthew Garrett
Date: Wed Dec 20 2006 - 22:26:29 EST


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 | mjg59@xxxxxxxxxxxxx
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