2009-12-16 22:53:52

by Samuel Ortiz

Subject: libertas driver carrier of signaling

Hi guys,

I was looking at the libertas driver and found that piece of code, at scan.c:

/* We want to scan all channels */
chan_count = lbs_scan_create_channel_list(priv, chan_list);

netif_stop_queue(priv->dev);
netif_carrier_off(priv->dev);

So, why do we need to turn carrier off when scanning? I could barely see why
we'd want to stop the netdev tx queue, but is turning carrier off really
needed ?

Thanks in advance for your answers.

Cheers,
Samuel.

--
Intel Open Source Technology Centre
http://oss.intel.com/

2009-12-17 01:18:36

by Dan Williams

Subject: Re: libertas driver carrier of signaling

On Wed, 2009-12-16 at 23:55 +0100, Samuel Ortiz wrote:
> Hi guys,
>
> I was looking at the libertas driver and found that piece of code, at scan.c:
>
> /* We want to scan all channels */
> chan_count = lbs_scan_create_channel_list(priv, chan_list);
>
> netif_stop_queue(priv->dev);
> netif_carrier_off(priv->dev);
>
> So, why do we need to turn carrier off when scanning? I could barely see why
> we'd want to stop the netdev tx queue, but is turning carrier off really
> needed ?

Probably not. Carrier is largely useless with wireless drivers anyway,
though if they for some reason really, really want to use carrier,
carrier should only be on when the device is authed & associated to an
AP.

Dan