This will be needed in the next patch.

Signed-off-by: Lukas Straub <lukasstraub2@web.de>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Zhang Chen <chen.zhang@intel.com>
---
 chardev/char.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/chardev/char.c b/chardev/char.c
index e77564060d..5c8014199f 100644
--- a/chardev/char.c
+++ b/chardev/char.c
@@ -38,6 +38,7 @@
 #include "qemu/module.h"
 #include "qemu/option.h"
 #include "qemu/id.h"
+#include "qemu/coroutine.h"
 
 #include "chardev/char-mux.h"
 
@@ -119,7 +120,11 @@ static int qemu_chr_write_buffer(Chardev *s,
     retry:
         res = cc->chr_write(s, buf + *offset, len - *offset);
         if (res < 0 && errno == EAGAIN && write_all) {
-            g_usleep(100);
+            if (qemu_in_coroutine()) {
+                qemu_co_sleep_ns(QEMU_CLOCK_REALTIME, 100000);
+            } else {
+                g_usleep(100);
+            }
             goto retry;
         }
 
-- 
2.20.1