Re: [PATCH v2] ath9k: fix dma mapping leak of rx buffer upon rmmod

["Luis R. Rodriguez" <lrodriguez@atheros.com>]

On Mon, Mar 23, 2009 at 05:21:28PM -0700, FUJITA Tomonori wrote:
> On Mon, 23 Mar 2009 18:25:01 -0400
> "Luis R. Rodriguez" <lrodriguez@atheros.com> wrote:
> 
> > We were claiming DMA buffers on the RX tasklet but never
> > upon a simple module removal.
> >
> > Cc: stable@kernel.org
> > Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
> > Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
> > ---
> >
> > Sorry, forgot to CC stable
> >
> >  drivers/net/wireless/ath9k/recv.c |    7 ++++++-
> >  1 files changed, 6 insertions(+), 1 deletions(-)
> >
> > diff --git a/drivers/net/wireless/ath9k/recv.c b/drivers/net/wireless/ath9k/recv.c
> > index 917bac7..71cb18d 100644
> > --- a/drivers/net/wireless/ath9k/recv.c
> > +++ b/drivers/net/wireless/ath9k/recv.c
> > @@ -344,8 +344,13 @@ void ath_rx_cleanup(struct ath_softc *sc)
> >
> >       list_for_each_entry(bf, &sc->rx.rxbuf, list) {
> >               skb = bf->bf_mpdu;
> > -             if (skb)
> > +             if (skb) {
> > +                     dma_unmap_single(sc->dev,
> > +                                      bf->bf_buf_addr,
> > +                                      sc->rx.bufsize,
> > +                                      DMA_FROM_DEVICE);
> >                       dev_kfree_skb(skb);
> > +             }
> >       }
> 
> ath9k uses pci_map/unmap_* families so using dma_map/unmap looks
> inconsistent. It works though.
> 
> I think that my original patch is fine:
> 
> http://marc.info/?l=linux-kernel&m=123725029228065&w=2

Noted -- the ported patch for 2.6.29 will use pci_unmap_single() however
this patch was for 2.6.30 where we now have bus-agnostic routines. To
get a better idea of how this looks feel free to check out ath9k from
the wireless-testing git tree.

git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-testing.git

  Luis