block: Compute minimum, maximum and average I/O latencies

[qemu.git] / hw / timer / i8254.c

diff --git a/hw/timer/i8254.c b/hw/timer/i8254.c
index 3450c98637da9afeb117b91bb11156ec2a42b070..9b65a336923f99d5277915820accafa976a3e45f 100644 (file)
--- a/hw/timer/i8254.c
+++ b/hw/timer/i8254.c
@@ -196,6 +196,12 @@ static uint64_t pit_ioport_read(void *opaque, hwaddr addr,
     PITChannelState *s;
 
     addr &= 3;
+
+    if (addr == 3) {
+        /* Mode/Command register is write only, read is ignored */
+        return 0;
+    }
+
     s = &pit->channels[addr];
     if (s->status_latched) {
         s->status_latched = 0;