On Tue, Mar 15, 2022 at 04:38:56PM +0100, Arnaud Pouliquen wrote:
> when a rpmsg channel has been locally created with a destination address
s/when/Wen
Also, please be more specific about the "locally created" part, i.e
rpmsg_ctrldev_ioctl() -> rpmsg_create_channel(). Otherwise it is really hard to
understand the context of this change.
> set to RPMSG_ADDR_ANY, a name service announcement message is sent to
> the remote side. Then the destination address is never updated, making it
> impossible to send messages to the remote.
>
> An example of kernel trace observed:
> rpmsg_tty virtio0.rpmsg-tty.29.-1: invalid addr (src 0x1d, dst 0xffffffff)
>
> Implement same strategy than the open-amp library:
> On the reception of the first message, if the destination address is
> RPMSG_ADDR_ANY, then set it to address of the remote endpoint that
> send the message.
>
I would have expected a "Fixes:" tag.
> Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@xxxxxxxxxxx>
>
> ---
> Remark:
> An alternative (or a complement?) could be to add a NS bind/unbind in
> the NS announcement channel (in rpmsg_ns.c).
> This would allow the local and/or the remote processor to inform the
> remote side the the service announced in bound.
> ---
> drivers/rpmsg/virtio_rpmsg_bus.c | 10 ++++++++++
> 1 file changed, 10 insertions(+)
>
> diff --git a/drivers/rpmsg/virtio_rpmsg_bus.c b/drivers/rpmsg/virtio_rpmsg_bus.c
> index 3ede25b1f2e4..99d2119cc164 100644
> --- a/drivers/rpmsg/virtio_rpmsg_bus.c
> +++ b/drivers/rpmsg/virtio_rpmsg_bus.c
> @@ -708,6 +708,7 @@ static ssize_t virtio_rpmsg_get_mtu(struct rpmsg_endpoint *ept)
> static int rpmsg_recv_single(struct virtproc_info *vrp, struct device *dev,
> struct rpmsg_hdr *msg, unsigned int len)
> {
> + struct rpmsg_device *rpdev;
> struct rpmsg_endpoint *ept;
> struct scatterlist sg;
> bool little_endian = virtio_is_little_endian(vrp->vdev);
> @@ -746,6 +747,15 @@ static int rpmsg_recv_single(struct virtproc_info *vrp, struct device *dev,
> mutex_unlock(&vrp->endpoints_lock);
>
> if (ept) {
> + rpdev = ept->rpdev;
> + if (rpdev->ept == ept && rpdev->dst == RPMSG_ADDR_ANY) {
Please add a comment to explain the first part of the if() clause. It took me
quite some time to understand.
> + /*
> + * First message received from the remote side on the default endpoint,
> + * update channel destination address.
> + */
> + rpdev->dst = msg->src;
This triggers a bot warning and should be addressed. If it can't be addressed add
a comment that clearly explains why so that we don't end up receiving patches
for it every 4 weeks.
Thanks,
Mathieu
> + }
> +
> /* make sure ept->cb doesn't go away while we use it */
> mutex_lock(&ept->cb_lock);
>
> --
> 2.25.1
>
