From 8a273cbe53221d28abfc98f33a0d057b26e53d6a Mon Sep 17 00:00:00 2001
From: Thomas Huth <thuth@redhat.com>
Date: Fri, 18 Nov 2016 10:09:37 +0100
Subject: [PATCH] hw/char/spapr_vty: Return amount of free buffer entries in
 vty_can_receive()

The can_receive() callbacks of the character devices should return
the amount of characters that can be accepted at once, not just a
boolean value (which rather means only one character at a time).

Signed-off-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
---
 hw/char/spapr_vty.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/hw/char/spapr_vty.c b/hw/char/spapr_vty.c
index 06b9b3917f..7c22b8bd0e 100644
--- a/hw/char/spapr_vty.c
+++ b/hw/char/spapr_vty.c
@@ -25,7 +25,7 @@ static int vty_can_receive(void *opaque)
 {
     VIOsPAPRVTYDevice *dev = VIO_SPAPR_VTY_DEVICE(opaque);
 
-    return (dev->in - dev->out) < VTERM_BUFSIZE;
+    return VTERM_BUFSIZE - (dev->in - dev->out);
 }
 
 static void vty_receive(void *opaque, const uint8_t *buf, int size)