Re: [PATCH v2] Bluetooth: Fix l2cap_tx_window_full

[Gustavo Padovan <padovan@profusion.mobi>]

Hi Andrei,

* Andrei Emeltchenko <andrei.emeltchenko.news@gmail.com> [2012-02-08 15:59:11 +0200]:

> Hi all,
> 
> On Wed, Feb 08, 2012 at 11:54:54AM -0200, Ulisses Furquim wrote:
> > Hi Luiz,
> > 
> > On Wed, Feb 8, 2012 at 11:47 AM, Luiz Augusto von Dentz
> > <luiz.dentz@gmail.com> wrote:
> > > From: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
> > >
> > > l2cap_tx_window_full is not checking the window limit properly, first it
> > > computes based on sequence numbers which doesn't take into account the
> > > ReqSeq and always assume 64 not the real window size.
> > >
> > > To fix this now it just checks if the number of unacked frames is >= of
> > > tx window which is much simpler.
> > >
> > > Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
> > > ---
> > > Add debug
> > >
> > >  include/net/bluetooth/l2cap.h |   10 +++-------
> > >  1 files changed, 3 insertions(+), 7 deletions(-)
> > >
> > > diff --git a/include/net/bluetooth/l2cap.h b/include/net/bluetooth/l2cap.h
> > > index 42fdbb8..bcfddb2 100644
> > > --- a/include/net/bluetooth/l2cap.h
> > > +++ b/include/net/bluetooth/l2cap.h
> > > @@ -661,14 +661,10 @@ static inline __u16 __next_seq(struct l2cap_chan *chan, __u16 seq)
> > >
> > >  static inline int l2cap_tx_window_full(struct l2cap_chan *ch)
> > >  {
> > > -       int sub;
> > > +       BT_DBG("chan %p unacked %d tx_win %d", ch, ch->unacked_frames,
> > > +                                                       ch->remote_tx_win);
> > >
> > > -       sub = (ch->next_tx_seq - ch->expected_ack_seq) % 64;
> > > -
> > > -       if (sub < 0)
> > > -               sub += 64;
> > > -
> > > -       return sub == ch->remote_tx_win;
> > > +       return ch->unacked_frames >= ch->remote_tx_win;
> > >  }
> > >
> > >  static inline __u16 __get_reqseq(struct l2cap_chan *chan, __u32 ctrl)
> > > --
> > > 1.7.7.6
> > 
> > Looks good to me.
> 
> Same here, I am wondering why it was done in a such complex way? Maybe
> there is some logic behind?

I followed the specification, next_tx_seq minus expecpted_ack_seq is the
definition of the current size of the tx_window.

Anyway,

Acked-by: Gustavo F. Padovan <padovan@profusion.mobi>

	Gustavo