Changeset 59230 in vbox

Timestamp:

Dec 29, 2015 10:02:39 PM (9 years ago)

Author:

vboxsync

Message:

BIOS: Made timeout more predictable.

File:

• trunk/src/VBox/Devices/PC/BIOS/ps2mouse.c (modified) (1 diff)

trunk/src/VBox/Devices/PC/BIOS/ps2mouse.c

@@ -75 +75 @@
 uint8_t get_mouse_data(uint8_t __far *data)
 {
-    int         retries = 10000;
+    int         retries = 10000;    /* ~150ms timeout */
     uint8_t     response;
 
     while ((inb(0x64) & 0x21) != 0x21 && retries)
+    {
+        /* Wait until the 15us refresh counter toggles. */
+        response = inb(0x61) & 0x10;
+        while((inb(0x61) & 0x10) == response)
+            ;
         --retries;
+    }
 
     if (!retries)