From: Christian Borntraeger <[email protected]> In rare cases a virtio command might try to issue a ccw before a former ccw was answered with a tsch. This will cause CC=2 (busy). Lets just retry in that case.
Signed-off-by: Christian Borntraeger <[email protected]> Signed-off-by: Cornelia Huck <[email protected]> --- drivers/s390/kvm/virtio_ccw.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) diff --git a/drivers/s390/kvm/virtio_ccw.c b/drivers/s390/kvm/virtio_ccw.c index 70419a7..2edd94a 100644 --- a/drivers/s390/kvm/virtio_ccw.c +++ b/drivers/s390/kvm/virtio_ccw.c @@ -132,11 +132,14 @@ static int ccw_io_helper(struct virtio_ccw_device *vcdev, unsigned long flags; int flag = intparm & VIRTIO_CCW_INTPARM_MASK; - spin_lock_irqsave(get_ccwdev_lock(vcdev->cdev), flags); - ret = ccw_device_start(vcdev->cdev, ccw, intparm, 0, 0); - if (!ret) - vcdev->curr_io |= flag; - spin_unlock_irqrestore(get_ccwdev_lock(vcdev->cdev), flags); + do { + spin_lock_irqsave(get_ccwdev_lock(vcdev->cdev), flags); + ret = ccw_device_start(vcdev->cdev, ccw, intparm, 0, 0); + if (!ret) + vcdev->curr_io |= flag; + spin_unlock_irqrestore(get_ccwdev_lock(vcdev->cdev), flags); + cpu_relax(); + } while (ret == -EBUSY); wait_event(vcdev->wait_q, doing_io(vcdev, flag) == 0); return ret ? ret : vcdev->err; } -- 1.7.12.4 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
