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[PATCH] USB: tweak highspeed timing calculations

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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>
This commit is contained in:
david-b@pacbell.net 2005-08-11 19:37:01 -07:00 committed by Greg Kroah-Hartman
parent 3b4d7f7916
commit f956e7cd9a
1 changed files with 4 additions and 4 deletions
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8
drivers/usb/core/hcd.h
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@ -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))