Re: [PATCH 3/5] Bluetooth: Clear ack_timer when sending ack

[Marcel Holtmann <marcel@holtmann.org>]

Hi Szymon,

> > > ack_timer should be cleared when sending ACK to avoid acking I-frames
> > > twice.
> > 
> > explain why you are creating a helper for it. Since that is clearly not
> > obvious to me.
> 
> To avoid code duplication - helper is not clearing ack timer and is used by
> both l2cap_send_ack and l2cap_ack_timeout.
> There is no need to clear ack timer in timer funtion.
> 
> But if you prefer to not have helper and are fine with clearing ack timer also in
> l2cap_ack_timeout then ack timer can be clear in l2cap_send_ack.

put that in the commit message please.

> > > 
> > > Signed-off-by: Szymon Janc <szymon.janc@tieto.com>
> > > ---
> > >  net/bluetooth/l2cap_core.c |   10 ++++++++--
> > >  1 files changed, 8 insertions(+), 2 deletions(-)
> > > 
> > > diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
> > > index 308d9d7..b9e232e 100644
> > > --- a/net/bluetooth/l2cap_core.c
> > > +++ b/net/bluetooth/l2cap_core.c
> > > @@ -1478,7 +1478,7 @@ static int l2cap_retransmit_frames(struct l2cap_chan *chan)
> > >  	return ret;
> > >  }
> > >  
> > > -static void l2cap_send_ack(struct l2cap_chan *chan)
> > > +static void __l2cap_send_ack(struct l2cap_chan *chan)
> > >  {
> > >  	u32 control = 0;
> > >  
> > > @@ -1498,6 +1498,12 @@ static void l2cap_send_ack(struct l2cap_chan *chan)
> > >  	l2cap_send_sframe(chan, control);
> > >  }
> > >  
> > > +static void l2cap_send_ack(struct l2cap_chan *chan)
> > > +{
> > > +	__clear_ack_timer(chan);
> > > +	__l2cap_send_ack(chan);
> > > +}
> > > +
> > >  static void l2cap_send_srejtail(struct l2cap_chan *chan)
> > >  {
> > >  	struct srej_list *tail;
> > > @@ -1988,7 +1994,7 @@ static void l2cap_ack_timeout(struct work_struct *work)
> > >  	BT_DBG("chan %p", chan);
> > >  
> > >  	lock_sock(chan->sk);
> > 
> > I would have just added
> > 
> > 	__clear_ack_timer(chan):
> > 
> > here.
> 
> This is a timer function so there is no need to clear timer here.
> 
> > > -	l2cap_send_ack(chan);
> > > +	__l2cap_send_ack(chan);
> > >  	release_sock(chan->sk);
> > >  }
> > >  

You are absolutely correct of course. I confused myself here. This also
means that either we add proper comments here or make it simpler to
follow the code. See what makes more sense.

Regards

Marcel