serial: Always update iir, even when ier is empty (Samuel Thibault)

This fixes installation of Windows XP.
Signed-off-by: NSamuel Thibault <samuel.thibault@eu.citrix.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>



git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@4995 c046a42c-6fe2-441c-8c8c-71466251a162

hw/serial.c

@@ -189,11 +189,6 @@ static void serial_update_irq(SerialState *s)
 {
     uint8_t tmp_iir = UART_IIR_NO_INT;
 
-    if (!s->ier) {
-        qemu_irq_lower(s->irq);
-        return;
-    }
-
     if ((s->ier & UART_IER_RLSI) && (s->lsr & UART_LSR_INT_ANY)) {
         tmp_iir = UART_IIR_RLSI;
     } else if (s->timeout_ipending) {