From 776a2489812fb0c369a10ddac282496055ef8c8f Mon Sep 17 00:00:00 2001
From: Aleksey Bragin <aleksey@reactos.org>
Date: Wed, 21 Nov 2007 11:18:15 +0000
Subject: [PATCH] - Remove stupid and greatly broken "let's wait in a loop,
 while querying current time" by calls to KeDelayExecutionThread().

svn path=/trunk/; revision=30620
---
 reactos/drivers/usb/nt4compat/usbdriver/usb.c | 76 +++----------------
 1 file changed, 10 insertions(+), 66 deletions(-)

diff --git a/reactos/drivers/usb/nt4compat/usbdriver/usb.c b/reactos/drivers/usb/nt4compat/usbdriver/usb.c
index 73859497e65..49dc4700dfa 100644
--- a/reactos/drivers/usb/nt4compat/usbdriver/usb.c
+++ b/reactos/drivers/usb/nt4compat/usbdriver/usb.c
@@ -1014,80 +1014,24 @@ LBL_OUT:
 VOID
 usb_wait_ms_dpc(ULONG ms)
 {
-    LARGE_INTEGER start;
-    LARGE_INTEGER ticker;
-    LARGE_INTEGER freq;
-    ULONG interval;
-    ULONG expire_count;
+    LARGE_INTEGER Interval;
+    if (ms <= 0)
+        return;
 
-    KeQueryPerformanceCounter(&freq);
-
-    expire_count = 2000000;
-    if (cpu_clock_freq)
-        expire_count = (cpu_clock_freq / 1000) * ms;
-
-    if (usb_query_clicks(&start) == FALSE)
-    {
-        ticker.QuadPart = 0;
-        while (TRUE)
-        {
-            KeQuerySystemTime(&ticker);
-            interval = ticker.LowPart - start.LowPart;
-            if (interval >= ms * 10000)
-                break;
-        }
-    }
-    else
-    {
-        ticker.QuadPart = 0;
-        while (TRUE)
-        {
-            usb_query_clicks(&ticker);
-            interval = ticker.LowPart - start.LowPart;
-            if (interval >= expire_count)
-                break;
-        }
-    }
+    Interval.QuadPart = -ms * 10000;
+    KeDelayExecutionThread(KernelMode, FALSE, &Interval);
 }
 
 
 VOID
 usb_wait_us_dpc(ULONG us)
 {
-    LARGE_INTEGER start;
-    LARGE_INTEGER ticker;
-    LARGE_INTEGER freq;
-    ULONG interval;
-    ULONG expire_count;
+    LARGE_INTEGER Interval;
+    if (us <= 0)
+        return;
 
-    KeQueryPerformanceCounter(&freq);
-
-    expire_count = 2000000;
-    if (cpu_clock_freq)
-        expire_count = (cpu_clock_freq / 1000000) * us;
-
-    if (usb_query_clicks(&start) == FALSE)
-    {
-        ticker.QuadPart = 0;
-        while (TRUE)
-        {
-            KeQuerySystemTime(&ticker);
-            interval = ticker.LowPart - start.LowPart;
-            if (interval >= us * 10)
-                break;
-        }
-    }
-    else
-    {
-        ticker.QuadPart = 0;
-        while (TRUE)
-        {
-            usb_query_clicks(&ticker);
-            interval = ticker.LowPart - start.LowPart;
-            if (interval >= expire_count)
-                break;
-        }
-    }
+    Interval.QuadPart = -us;
+    KeDelayExecutionThread(KernelMode, FALSE, &Interval);
 }
 
 VOID