Fix inactive timer list corruption on second S3 resume

init_timer cannot be safely called multiple times on same timer since it does memset(0)
on the structure, erasing the auxiliary member used by linked list code. This breaks
inactive timer list in common/timer.c.

Moved resume_timer initialisation to ns16550_init_postirq, so it's only done once.

Signed-off-by: Tomasz Wroblewski <tomasz.wroblewski@citrix.com>
Acked-by: Keir Fraser <keir@xen.org>
master commit: 9e2c593824
master date: 2013-08-28 10:18:39 +0200

xen/drivers/char/ns16550.c

@@ -128,6 +128,8 @@ static struct ns16550 {
 #define RESUME_DELAY    MILLISECS(10)
 #define RESUME_RETRIES  100
 
+static void ns16550_delayed_resume(void *data);
+
 static char ns_read_reg(struct ns16550 *uart, int reg)
 {
     if ( uart->remapped_io_base == NULL )
@@ -323,6 +325,7 @@ static void __init ns16550_init_postirq(struct serial_port *port)
     serial_async_transmit(port);
 
     init_timer(&uart->timer, ns16550_poll, port, 0);
+    init_timer(&uart->resume_timer, ns16550_delayed_resume, port, 0);
 
     /* Calculate time to fill RX FIFO and/or empty TX FIFO for polling. */
     bits = uart->data_bits + uart->stop_bits + !!uart->parity;
@@ -413,7 +416,6 @@ static void ns16550_resume(struct serial_port *port)
     if ( ns16550_ioport_invalid(uart) )
     {
         delayed_resume_tries = RESUME_RETRIES;
-        init_timer(&uart->resume_timer, ns16550_delayed_resume, port, 0);
         set_timer(&uart->resume_timer, NOW() + RESUME_DELAY);
     }
     else