Support USB interrupt schedules on OHCI and UHCI.

The existing code always checks for USB "interrupt in" events every
millisecond.  Although that's okay, it consumes extra bandwidth.  This
change interrupt checks to be scheduled according to their requested
interval time.

1 files changed, 2 insertions, 0 deletions

diff --git a/src/util.h b/src/util.h
index 60a7259..429590c 100644
--- a/src/util.h
+++ b/src/util.h
@@ -245,6 +245,8 @@ void serial_setup(void);
 void lpt_setup(void);
 
 // clock.c
+#define PIT_TICK_RATE 1193180   // Underlying HZ of PIT
+#define PIT_TICK_INTERVAL 65536 // Default interval for 18.2Hz timer
 static inline int check_time(u64 end) {
     return (s64)(rdtscll() - end) > 0;
 }