Re: [PATCH 1/1] New driver: rtl8xxxu (mac80211)

[Johannes Berg <johannes@sipsolutions.net>]

On Mon, 2015-10-05 at 15:19 -0400, Jes Sorensen wrote:
> Johannes Berg <johannes@sipsolutions.net> writes:
> > On Mon, 2015-10-05 at 15:04 -0400, Jes Sorensen wrote:
> > > 
> > > I have this in the code - that said, I may not be getting a 
> > > pointer 
> > > back ever?
> > > 
> > > 	if (changed & BSS_CHANGED_ERP_PREAMBLE) {
> > > ...
> > > 		sta = ieee80211_find_sta(vif, bss_conf->bssid);
> > > 		if (sta) {
> > > 			sta_priv = (struct rtl8xxxu_sta_priv 
> > > *)sta
> > > ->drv_priv;
> > > 			if (bss_conf->use_short_preamble)
> > > 				sta_priv->short_preamble = true;
> > > 			else
> > > 				sta_priv->short_preamble = 
> > > false;
> > > 
> > 
> > Ah, ok. You'd of course get a pointer back here - but it's 
> > pointless.
> > 
> > You might as well store the value in some private vif data, or 
> > perhaps
> > just use vif->bss_conf.use_short_preamble in the place that you're 
> > now
> > using sta_priv->short_preamble - the point was that a per-station
> > setting of short-preamble doesn't make sense, it needs to be per
> > -vif.
> 
> I see - what is the correct way to get to the vif from with the .tx()
> function then?
> 

You have a pointer right there in the skb's cb (info) [though it might
be NULL in some rare cases]

johannes