vioblk: Properly handle poll timeout

The only way to ensure that the device does not do DMA for the timed out
request is a device reset.

Also increase the timeout to 15s

diff --git a/sys/dev/pci/vioblk.c b/sys/dev/pci/vioblk.c
index 947f873..857f22f 100644 (file)
--- a/sys/dev/pci/vioblk.c
+++ b/sys/dev/pci/vioblk.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: vioblk.c,v 1.11 2016/07/14 12:44:53 sf Exp $  */
+/*     $OpenBSD: vioblk.c,v 1.12 2016/07/14 12:50:07 sf Exp $  */
 
 /*
  * Copyright (c) 2012 Stefan Fritsch.
@@ -116,6 +116,7 @@ int vioblk_alloc_reqs(struct vioblk_softc *, int);
 int    vioblk_vq_done(struct virtqueue *);
 void   vioblk_vq_done1(struct vioblk_softc *, struct virtio_softc *,
                        struct virtqueue *, int);
+void   vioblk_reset(struct vioblk_softc *);
 
 void   vioblk_scsi_cmd(struct scsi_xfer *);
 int    vioblk_dev_probe(struct scsi_link *);
@@ -304,6 +305,32 @@ vioblk_vq_done1(struct vioblk_softc *sc, struct virtio_softc *vsc,
        virtio_dequeue_commit(vq, slot);
 }
 
+void
+vioblk_reset(struct vioblk_softc *sc)
+{
+       int i;
+
+       /* reset device to stop DMA */
+       virtio_reset(sc->sc_virtio);
+
+       /* finish requests that have been completed */
+       vioblk_vq_done(&sc->sc_vq[0]);
+
+       /* abort all remaining requests */
+       for (i = 0; i < sc->sc_link.openings; i++) {
+               struct virtio_blk_req *vr = &sc->sc_reqs[i];
+               struct scsi_xfer *xs = vr->vr_xs;
+
+               if (vr->vr_len == VIOBLK_DONE)
+                       continue;
+
+               xs->error = XS_DRIVER_STUFFUP;
+               xs->resid = xs->datalen;
+               scsi_done(xs);
+               vr->vr_len = VIOBLK_DONE;
+       }
+}
+
 void
 vioblk_scsi_cmd(struct scsi_xfer *xs)
 {
@@ -458,13 +485,22 @@ vioblk_scsi_cmd(struct scsi_xfer *xs)
                return;
        }
 
-       timeout = 1000;
+       timeout = 15 * 1000;
        do {
                if (virtio_poll_intr(vsc) && vr->vr_len == VIOBLK_DONE)
                        break;
 
                delay(1000);
        } while(--timeout > 0);
+       if (timeout <= 0) {
+               uint32_t features;
+               printf("%s: SCSI_POLL timed out\n", __func__);
+               vioblk_reset(sc);
+               virtio_reinit_start(vsc);
+               features = virtio_negotiate_features(vsc, vsc->sc_features,
+                   NULL);
+               KASSERT(features == vsc->sc_features);
+       }
        splx(s);
        return;