[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>

diff --git a/drivers/usb/core/hcd.h b/drivers/usb/core/hcd.h
index 28055f9..ac451fa 100644 (file)
--- a/drivers/usb/core/hcd.h
+++ b/drivers/usb/core/hcd.h
@@ -339,11 +339,11 @@ extern int usb_check_bandwidth (struct usb_device *dev, struct urb *urb);
  * 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))