diff options
| author | Michael S. Tsirkin <mst@redhat.com> | 2015-03-12 11:54:41 +1030 |
|---|---|---|
| committer | Rusty Russell <rusty@rustcorp.com.au> | 2015-03-13 15:55:42 +1030 |
| commit | 71e4b8bf0482fc7d70e9d4c10b13c207a285d58a (patch) | |
| tree | 435db3fcf8c9e28fdc331b64fb0f4effb80b3138 /drivers/rpmsg | |
| parent | 8051a2a518fcf3827a143470083ad6008697ff17 (diff) | |
| download | linux-71e4b8bf0482fc7d70e9d4c10b13c207a285d58a.tar.bz2 | |
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 <mst@redhat.com>
Acked-by: Ohad Ben-Cohen <ohad@wizery.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Diffstat (limited to 'drivers/rpmsg')
| -rw-r--r-- | drivers/rpmsg/virtio_rpmsg_bus.c | 17 |
1 files changed, 16 insertions, 1 deletions
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"); |