commit f956e7cd9ac4618b98022020e638bbdc01d9d65a
author david-b@pacbell.net <david-b@pacbell.net> Thu Aug 11 19:37:01 2005 -0700
committer Greg Kroah-Hartman <gregkh@suse.de> Thu Sep 08 16:28:25 2005 -0700
tree d727c96bda9882323bf84b56d2dd09c9fb5e39b0
parent 3b4d7f79164853e10342d707e32307e0c8054982

[PATCH] USB: tweak highspeed timing calculations

Use a more correct calculation for highspeed bit times.

  http://bugzilla.kernel.org/show_bug.cgi?id=3604

This sort if thing might start to make a difference now that the high
speed periodic scheduler is more complete -- and even getting used.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/core/hcd.h

diff --git a/drivers/usb/core/hcd.h b/drivers/usb/core/hcd.h
index 28055f9..ac451fa 100644
--- a/drivers/usb/core/hcd.h
+++ b/drivers/usb/core/hcd.h
@@ -339,11 +339,11 @@
  * to preallocate bandwidth)
  */
 #define USB2_HOST_DELAY	5	/* nsec, guess */
-#define HS_NSECS(bytes) ( ((55 * 8 * 2083)/1000) \
-	+ ((2083UL * (3167 + BitTime (bytes)))/1000) \
+#define HS_NSECS(bytes) ( ((55 * 8 * 2083) \
+	+ (2083UL * (3 + BitTime(bytes))))/1000 \
 	+ USB2_HOST_DELAY)
-#define HS_NSECS_ISO(bytes) ( ((38 * 8 * 2083)/1000) \
-	+ ((2083UL * (3167 + BitTime (bytes)))/1000) \
+#define HS_NSECS_ISO(bytes) ( ((38 * 8 * 2083) \
+	+ (2083UL * (3 + BitTime(bytes))))/1000 \
 	+ USB2_HOST_DELAY)
 #define HS_USECS(bytes) NS_TO_US (HS_NSECS(bytes))
 #define HS_USECS_ISO(bytes) NS_TO_US (HS_NSECS_ISO(bytes))