If the system runs out ouf mbufs, the receive queue of the vio

interface may get emtpy.  The driver did not recover from that
starvation as it does not get receive interrupts anymore.  Fix this
by adding a one second receive timeout in that case.
OK sf@

1 files changed, 29 insertions, 8 deletions

diff --git a/sys/dev/pci/if_vio.c b/sys/dev/pci/if_vio.c
index ef89bb104e0..cd6d419b834 100644
--- a/sys/dev/pci/if_vio.c
+++ b/sys/dev/pci/if_vio.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: if_vio.c,v 1.14 2014/01/08 22:24:35 bluhm Exp $	*/
+/*	$OpenBSD: if_vio.c,v 1.15 2014/01/19 20:49:02 bluhm Exp $	*/
 
 /*
  * Copyright (c) 2012 Stefan Fritsch, Alexander Fiveg.
@@ -219,7 +219,7 @@ struct vio_softc {
 
 	enum vio_ctrl_state	sc_ctrl_inuse;
 
-	struct timeout		sc_tick;
+	struct timeout		sc_txtick, sc_rxtick;
 };
 
 #define VIO_DMAMEM_OFFSET(sc, p) ((caddr_t)(p) - (sc)->sc_dma_kva)
@@ -260,6 +260,7 @@ void	vio_populate_rx_mbufs(struct vio_softc *);
 int	vio_rxeof(struct vio_softc *);
 int	vio_rx_intr(struct virtqueue *);
 void	vio_rx_drain(struct vio_softc *);
+void	vio_rxtick(void *);
 
 /* tx */
 int	vio_tx_intr(struct virtqueue *);
@@ -588,7 +589,8 @@ vio_attach(struct device *parent, struct device *self, void *aux)
 	ifmedia_set(&sc->sc_media, IFM_ETHER | IFM_AUTO);
 	vsc->sc_config_change = vio_config_change;
 	m_clsetwms(ifp, MCLBYTES, 4, sc->sc_vq[VQRX].vq_num);
-	timeout_set(&sc->sc_tick, vio_txtick, &sc->sc_vq[VQTX]);
+	timeout_set(&sc->sc_txtick, vio_txtick, &sc->sc_vq[VQTX]);
+	timeout_set(&sc->sc_rxtick, vio_rxtick, &sc->sc_vq[VQRX]);
 
 	if_attach(ifp);
 	ether_ifattach(ifp);
@@ -672,7 +674,8 @@ vio_stop(struct ifnet *ifp, int disable)
 	struct vio_softc *sc = ifp->if_softc;
 	struct virtio_softc *vsc = sc->sc_virtio;
 
-	timeout_del(&sc->sc_tick);
+	timeout_del(&sc->sc_txtick);
+	timeout_del(&sc->sc_rxtick);
 	ifp->if_flags &= ~(IFF_RUNNING | IFF_OACTIVE);
 	/* only way to stop I/O and DMA is resetting... */
 	virtio_reset(vsc);
@@ -781,7 +784,7 @@ again:
 
 	if (queued > 0) {
 		virtio_notify(vsc, vq);
-		timeout_add_sec(&sc->sc_tick, 1);
+		timeout_add_sec(&sc->sc_txtick, 1);
 	}
 }
 
@@ -795,7 +798,8 @@ vio_dump(struct vio_softc *sc)
 	printf("%s status dump:\n", ifp->if_xname);
 	printf("TX virtqueue:\n");
 	virtio_vq_dump(&vsc->sc_vqs[VQTX]);
-	printf("tx tick active: %d\n", !timeout_triggered(&sc->sc_tick));
+	printf("tx tick active: %d\n", !timeout_triggered(&sc->sc_txtick));
+	printf("rx tick active: %d\n", !timeout_triggered(&sc->sc_rxtick));
 	printf("RX virtqueue:\n");
 	virtio_vq_dump(&vsc->sc_vqs[VQRX]);
 	if (vsc->sc_nvqs == 3) {
@@ -941,6 +945,10 @@ vio_populate_rx_mbufs(struct vio_softc *sc)
 	}
 	if (ndone > 0)
 		virtio_notify(vsc, vq);
+	if (vq->vq_used_idx != vq->vq_avail_idx)
+		timeout_del(&sc->sc_rxtick);
+	else
+		timeout_add_sec(&sc->sc_rxtick, 1);
 }
 
 /* dequeue received packets */
@@ -1025,6 +1033,19 @@ again:
 	return sum;
 }
 
+void
+vio_rxtick(void *arg)
+{
+	struct virtqueue *vq = arg;
+	struct virtio_softc *vsc = vq->vq_owner;
+	struct vio_softc *sc = (struct vio_softc *)vsc->sc_child;
+	int s;
+
+	s = splnet();
+	vio_populate_rx_mbufs(sc);
+	splx(s);
+}
+
 /* free all the mbufs; called from if_stop(disable) */
 void
 vio_rx_drain(struct vio_softc *sc)
@@ -1103,9 +1124,9 @@ vio_txeof(struct virtqueue *vq)
 		virtio_stop_vq_intr(vsc, &sc->sc_vq[VQTX]);
 	}
 	if (vq->vq_used_idx == vq->vq_avail_idx)
-		timeout_del(&sc->sc_tick);
+		timeout_del(&sc->sc_txtick);
 	else if (r)
-		timeout_add_sec(&sc->sc_tick, 1);
+		timeout_add_sec(&sc->sc_txtick, 1);
 	return r;
 }