From 71e4b8bf0482fc7d70e9d4c10b13c207a285d58a Mon Sep 17 00:00:00 2001 From: "Michael S. Tsirkin" Date: Thu, 12 Mar 2015 11:54:41 +1030 Subject: virtio_rpmsg: set DRIVER_OK before using device virtio spec requires that all drivers set DRIVER_OK before using devices. While rpmsg isn't yet included in the virtio 1 spec, previous spec versions also required this. virtio rpmsg violates this rule: is calls kick before setting DRIVER_OK. The fix isn't trivial since simply calling virtio_device_ready earlier would mean we might get an interrupt in parallel with adding buffers. Instead, split kick out to prepare+notify calls. prepare before virtio_device_ready - when we know we won't get interrupts. notify right afterwards. Signed-off-by: Michael S. Tsirkin Acked-by: Ohad Ben-Cohen Signed-off-by: Rusty Russell --- drivers/rpmsg/virtio_rpmsg_bus.c | 17 ++++++++++++++++- 1 file changed, 16 insertions(+), 1 deletion(-) (limited to 'drivers/rpmsg') diff --git a/drivers/rpmsg/virtio_rpmsg_bus.c b/drivers/rpmsg/virtio_rpmsg_bus.c index 92f6af6da699..73354ee27877 100644 --- a/drivers/rpmsg/virtio_rpmsg_bus.c +++ b/drivers/rpmsg/virtio_rpmsg_bus.c @@ -951,6 +951,7 @@ static int rpmsg_probe(struct virtio_device *vdev) void *bufs_va; int err = 0, i; size_t total_buf_space; + bool notify; vrp = kzalloc(sizeof(*vrp), GFP_KERNEL); if (!vrp) @@ -1030,8 +1031,22 @@ static int rpmsg_probe(struct virtio_device *vdev) } } + /* + * Prepare to kick but don't notify yet - we can't do this before + * device is ready. + */ + notify = virtqueue_kick_prepare(vrp->rvq); + + /* From this point on, we can notify and get callbacks. */ + virtio_device_ready(vdev); + /* tell the remote processor it can start sending messages */ - virtqueue_kick(vrp->rvq); + /* + * this might be concurrent with callbacks, but we are only + * doing notify, not a full kick here, so that's ok. + */ + if (notify) + virtqueue_notify(vrp->rvq); dev_info(&vdev->dev, "rpmsg host is online\n"); -- cgit v1.2.1