From: Michael Buesch <mb@bu3sch.de>
To: "Alina Friedrichsen" <x-alina@gmx.net>
Subject: Re: [PATCH] b43: Accessing the TSF via mac80211
Date: Sun, 25 Jan 2009 13:55:49 +0100
Cc: linux-wireless@vger.kernel.org, linville@tuxdriver.com,
	johannes@sipsolutions.net
References: <20090125124151.115210@gmx.net> <200901251351.50230.mb@bu3sch.de>
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On Sunday 25 January 2009 13:51:50 Michael Buesch wrote:
> On Sunday 25 January 2009 13:41:51 Alina Friedrichsen wrote:
> > This allows the mac80211 high level code to access the TSF. This is e.g. needed for BSSID merges in the IBSS mode.
> 
> Thanks, can you also remove our private debugfs hook?
> 
> > Signed-off-by: Alina Friedrichsen <x-alina@gmx.net>
> > ---
> > diff -urN wireless-testing.orig/drivers/net/wireless/b43/main.c wireless-testing/drivers/net/wireless/b43/main.c
> > --- wireless-testing.orig/drivers/net/wireless/b43/main.c	2009-01-25 06:12:13.000000000 +0100
> > +++ wireless-testing/drivers/net/wireless/b43/main.c	2009-01-25 13:09:35.000000000 +0100
> > @@ -3177,6 +3177,25 @@
> >  	return 0;
> >  }
> >  
> > +static u64 b43_op_get_tsf(struct ieee80211_hw *hw)
> > +{
> > +	struct b43_wl *wl = hw_to_b43_wl(hw);
> > +	struct b43_wldev *dev = wl->current_dev;
> > +	u64 tsf;
> > +
> 
> You must add a check and locking here.
> 
> 	if (dev && (b43_status(dev) >= B43_STAT_INITIALIZED)) {
> 		mutex_lock(&wl->mutex);
> 		spin_lock_irq(&wl->irq_lock);
> 
> > +	b43_tsf_read(dev, &tsf);
> 
> 		spin_unlock_irq(&wl->irq_lock);
> 		mutex_unlock(&wl->mutex);
> 	} else
> 		tsf = 0; //FIXME what to do on error?
> 
> > +	return tsf;
> > +}

Whoops, I got it wrong :D
This is what it should look like:

static u64 b43_op_get_tsf(struct ieee80211_hw *hw)
{
       struct b43_wl *wl = hw_to_b43_wl(hw);
       struct b43_wldev *dev = wl->current_dev;
       u64 tsf;

	mutex_lock(&wl->mutex);
	spin_lock_irq(&wl->irq_lock);
	if (dev && (b43_status(dev) >= B43_STAT_INITIALIZED))
		b43_tsf_read(dev, &tsf);
	else
		tsf = 0;//FIXME? what to do on error?
	spin_unlock_irq(&wl->irq_lock);
	mutex_unlock(&wl->mutex);

       return tsf;
}

-- 
Greetings, Michael.