$NetBSD: patch-ba,v 1.1 2007/12/24 10:18:22 apb Exp $

--- hw/pcspk.c.orig	2007-02-06 01:01:54.000000000 +0200
+++ hw/pcspk.c
@@ -38,7 +38,6 @@ typedef struct {
     unsigned int samples;
     unsigned int play_pos;
     int data_on;
-    int dummy_refresh_clock;
 } PCSpkState;
 
 static const char *s_spk = "pcspk";
@@ -112,15 +111,32 @@ int pcspk_audio_init(AudioState *audio)
     return 0;
 }
 
+/*
+ * Emulate the speaker port's refresh clock bit.  This is supposed
+ * to toggle between 0 and 1<<4 every 15 microseconds.  XXX: We use
+ * gettimeofday() in the real machine instead of a monotonic clock
+ * in the virtual machine, and we are a bit sloppy about the 15
+ * microseconds.  This should be good enough for crude loops that
+ * measure approximate delays by counting how often this line toggles.
+ */
+static uint32_t pcspk_dummy_refresh_clock(void)
+{
+    struct timeval tv;
+
+    gettimeofday(&tv, NULL);
+    return ((tv.tv_sec ^ (tv.tv_usec / 15)) & 1) << 4;
+}
+
 static uint32_t pcspk_ioport_read(void *opaque, uint32_t addr)
 {
     PCSpkState *s = opaque;
     int out;
+    int dummy_refresh_clock;
 
-    s->dummy_refresh_clock ^= (1 << 4);
     out = pit_get_out(s->pit, 2, qemu_get_clock(vm_clock)) << 5;
 
-    return pit_get_gate(s->pit, 2) | (s->data_on << 1) | s->dummy_refresh_clock | out;
+    return pit_get_gate(s->pit, 2) | (s->data_on << 1) |
+	pcspk_dummy_refresh_clock() | out;
 }
 
 static void pcspk_ioport_write(void *opaque, uint32_t addr, uint32_t val)