Re: [PATCH 7/7] virtio: console: Return -EPIPE if port on the host isn't connected

["Michael S. Tsirkin" <mst@redhat.com>]

On Tue, Mar 23, 2010 at 02:28:00PM +0530, Amit Shah wrote:
> The virtio-serial ports are like pipes, if there's no reader on the
> other end, sending data might get it either ignored or the host might
> return '0', which would make guests get -EAGAIN. Since we know the state
> of the host port connection, it's appropriate to let the application
> know that the other end isn't connected.
> 
> Signed-off-by: Amit Shah <amit.shah@redhat.com>
> ---
>  drivers/char/virtio_console.c |    3 +++
>  1 files changed, 3 insertions(+), 0 deletions(-)
> 
> diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c
> index 55de0b5..4562964 100644
> --- a/drivers/char/virtio_console.c
> +++ b/drivers/char/virtio_console.c
> @@ -411,6 +411,9 @@ static ssize_t send_buf(struct port *port, void *in_buf, size_t in_count)
>  	ssize_t ret;
>  	unsigned int len;
>  
> +	if (use_multiport(port->portdev) && !port->host_connected)
> +		return -EPIPE;
> +

Hmm, do applications actually handle this error?

>  	out_vq = port->out_vq;
>  
>  	sg_init_one(sg, in_buf, in_count);
> -- 
> 1.6.2.5