[RFC PATCH 08/22] rpmsg: virtio_rpmsg_bus: Disable receive virtqueue callback when reading messages

Kishon Vijay Abraham I
2020-07-02T08:25:36Z

Since rpmsg_recv_done() reads messages in a while loop, disable
callbacks until the while loop exits. This helps to get rid of the
annoying "uhm, incoming signal, but no used buffer ?" message.

Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
---
drivers/rpmsg/virtio_rpmsg_bus.c | 14 ++++++++++++++
1 file changed, 14 insertions(+)

diff --git a/drivers/rpmsg/virtio_rpmsg_bus.c b/drivers/rpmsg/virtio_rpmsg_bus.c
index 376ebbf880d6..2d0d42084ac0 100644
--- a/drivers/rpmsg/virtio_rpmsg_bus.c
+++ b/drivers/rpmsg/virtio_rpmsg_bus.c
@@ -777,6 +777,7 @@ static void rpmsg_recv_done(struct virtqueue *rvq)
return;
}

+ virtqueue_disable_cb(rvq);
while (msg) {
err = rpmsg_recv_single(vrp, dev, msg, len);
if (err)
@@ -786,6 +787,19 @@ static void rpmsg_recv_done(struct virtqueue *rvq)

msg = virtqueue_get_buf(rvq, &len);
}
+ virtqueue_enable_cb(rvq);
+
+ /*
+ * Try to read message one more time in case a new message is submitted
+ * after virtqueue_get_buf() inside the while loop but before enabling
+ * callbacks
+ */
+ msg = virtqueue_get_buf(rvq, &len);
+ if (msg) {
+ err = rpmsg_recv_single(vrp, dev, msg, len);
+ if (!err)
+ msgs_received++;
+ }

dev_dbg(dev, "Received %u messages\n", msgs_received);

--
2.17.1