[Xen-devel] [Patch 1/5] rombios/keyboard: Don't needlessly poll the status register

[Andrew Cooper <andrew.cooper3@xxxxxxxxxx>]

Repeated polling of the status register is not going to change its value, so
don't needlessly take 8192 traps to Qemu when 1 will do.

Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
CC: Keir Fraser <keir@xxxxxxx>
---
 tools/firmware/rombios/rombios.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tools/firmware/rombios/rombios.c b/tools/firmware/rombios/rombios.c
index 80980b6..e364759 100644
--- a/tools/firmware/rombios/rombios.c
+++ b/tools/firmware/rombios/rombios.c
@@ -1805,12 +1805,12 @@ keyboard_init()
     while ( (inb(0x64) & 0x02) && (--max>0)) outb(0x80, 0x00);
 
     /* flush incoming keys */
-    max=0x2000;
+    max=2;
     while (--max > 0) {
         outb(0x80, 0x00);
         if (inb(0x64) & 0x01) {
             inb(0x60);
-            max = 0x2000;
+            max = 2;
             }
         }
 
-- 
1.7.10.4


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel