[PATCH] b43: use rx desc underrun interrupt

[Michael Büsch]

On Sun, 21 Apr 2013 20:39:49 +0200
Thommy Jakobsson <thommyj at gmail.com> wrote:

> On Apr 21, 2013 8:26 PM, "Michael Büsch" <m at bues.ch> wrote:
> >
> > On Sun, 21 Apr 2013 20:07:39 +0200 (CEST)
> > Thommy Jakobsson <thommyj at gmail.com> wrote:
> >
> > > +void b43_dma_rx_discard(struct b43_dmaring *ring)
> > > +{
> > > +     int current_slot, previous_slot;
> > > +
> > > +     B43_WARN_ON(ring->tx);
> > > +
> > > +     /* Device has filled all buffers, drop all packets in buffers
> > > +     * and let TCP decrease speed.
> > > +     * Set index to one desc after the last one
> > > +     * so the device will see all slots as free again
> > > +     */
> > > +     /*
> > > +     *TODO: How to increase rx_drop in mac80211?
> > > +     */
> > > +     current_slot = ring->ops->get_current_rxslot(ring);
> > > +     previous_slot = prev_slot(ring, current_slot);
> > > +     ring->ops->set_current_rxslot(ring, previous_slot);
> >
> > Hmmm. While this does work (because the register and ring->current_slot
> contain the same
> > value at this point), I'd prefer if you write ring->current_slot - 1
> > to the stop-index-register.
> The reason for the interrupt is because the current index in the device is
> the same as the last index. That's why I read the value from the device.
> But I fix it, don't have a strong opinion about it.

Hm, ok. Well, sounds plausible. So you may keep it as-is.

But you should probably rename the function to b43_dma_handle_rx_overflow(),
because the discard does not work properly, if the function is called without
an overflow in progress.

-- 
Michael
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