[RFC 1/1] libertas: new scan logic

[Holger Schurig]

I'm now at home (without the hardware) and tomorrow at a customer,
so I'll this will be just a VERY rant about things that come to mind.

> Maybe add some comments here about the magic numbers, ie something about
> making the basic rates marked the way the firmware expects.

Good idea.



> So here you're now blocking until the scan is complete.  We don't really
> want to do that...

Looks like you didn't run the code??? :-)

When the interface is first brought up and you (or the network scripts)
do an initial "iwlist eth1 essid MUMBLEFUTZ", then it does a full scan,
over all 11/13/14 channels, in one go and blocking. It doesn't use
the worker thread than. In this case the code blocks.

But when you later run "iwlist eth1 scan", then lbs_set_scan() merely
starts the worker thread for the scanning. Inside this thread it again
blocks, but this doesn't matter for the user-space application. Even
with strace, you can see that the SIWSCAN returns (almost) immediately.
iwlist than spends it's time called 3-6 times calling GIWSCAN ioctl,
which ends up in lbs_get_scan(), and returns (2-5 times) immediately with
-EAGAIN. Again nothing blocks, at least not the user-space.

You should have known that it doesn't block, because before I had the
-EAGAIN added, my problem was that "iwlist eth1 scan" returned
prematurely :-)



> The scan command should just be fired off

This is what lbs_set_scan() does.



> I haven't looked deeply enough, but are you sure the chan_count stuff
> will do what you want here?  If adapter->last_scanned_channel = 11...

When I run this code, the last_scanned_channel is first 0, then 4, then 8,
then 12 (in this case it only scans 3 channels). So yes, the channel
number and the index into the channel list are advanced correctly. And
with "lbsdebug +host +hex" you can see that it adds different TLVs for
the channel information to the CMD_802_11_SCAN command.



Then identation problems that were in the [RFC] patch don't exist
in the submitted [PATCH].


Thanks for looking throught and giving input :-)