wil_ring_next_tail
vring->swtail = wil_ring_next_tail(vring);
vring->swtail = wil_ring_next_tail(vring);
vring->swtail = wil_ring_next_tail(vring);
for (; next_tail = wil_ring_next_tail(v),
return wil_ring_next_tail(ring) == ring->swhead;
ring->swtail = wil_ring_next_tail(ring);
ring->swtail = wil_ring_next_tail(ring);
ring->swtail = wil_ring_next_tail(ring);