[Qemu-devel] [PATCH v2 1/1] char/serial: Fix emptyness handling

[Don Slutz <dslutz@verizon.com>]

The commit 88c1ee73d3231c74ff90bcfc084a7589670ec244
char/serial: Fix emptyness check

Still causes extra NULL byte(s) to be sent.

So if the fifo is empty, do not send an extra NULL byte.
Do full state change on fifo8_is_empty.

Signed-off-by: Don Slutz <dslutz@verizon.com>
---
v1 to v2:  Do all the state changes that would have been done sending the NULL byte.

 hw/char/serial.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/hw/char/serial.c b/hw/char/serial.c
index 6d3b5af..7af3c1b 100644
--- a/hw/char/serial.c
+++ b/hw/char/serial.c
@@ -225,8 +225,13 @@ static gboolean serial_xmit(GIOChannel *chan, GIOCondition cond, void *opaque)
 
     if (s->tsr_retry <= 0) {
         if (s->fcr & UART_FCR_FE) {
-            s->tsr = fifo8_is_empty(&s->xmit_fifo) ?
-                        0 : fifo8_pop(&s->xmit_fifo);
+            if (fifo8_is_empty(&s->xmit_fifo)) {
+                s->lsr |= UART_LSR_THRE | UART_LSR_TEMT;
+                s->thr_ipending = 1;
+                serial_update_irq(s);
+                return FALSE;
+            }
+            s->tsr = fifo8_pop(&s->xmit_fifo);
             if (!s->xmit_fifo.num) {
                 s->lsr |= UART_LSR_THRE;
             }
-- 
1.8.4