Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit f956e7cd authored by David Brownell's avatar David Brownell Committed by Greg Kroah-Hartman
Browse files

[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: default avatarDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 3b4d7f79

drivers/usb/core/hcd.h

+4 −4
Original line number Original line Diff line number Diff line
@@ -339,11 +339,11 @@ extern int usb_check_bandwidth (struct usb_device *dev, struct urb *urb); 
 * to preallocate bandwidth)

 * to preallocate bandwidth)

 */

 */

#define USB2_HOST_DELAY	5	/* nsec, guess */

#define USB2_HOST_DELAY	5	/* nsec, guess */

#define HS_NSECS(bytes) ( ((55 * 8 * 2083)/1000) \

#define HS_NSECS(bytes) ( ((55 * 8 * 2083) \

	+ ((2083UL * (3167 + BitTime (bytes)))/1000) \

	+ (2083UL * (3 + BitTime(bytes))))/1000 \

	+ USB2_HOST_DELAY)

	+ USB2_HOST_DELAY)

#define HS_NSECS_ISO(bytes) ( ((38 * 8 * 2083)/1000) \

#define HS_NSECS_ISO(bytes) ( ((38 * 8 * 2083) \

	+ ((2083UL * (3167 + BitTime (bytes)))/1000) \

	+ (2083UL * (3 + BitTime(bytes))))/1000 \

	+ USB2_HOST_DELAY)

	+ USB2_HOST_DELAY)

#define HS_USECS(bytes) NS_TO_US (HS_NSECS(bytes))

#define HS_USECS(bytes) NS_TO_US (HS_NSECS(bytes))

#define HS_USECS_ISO(bytes) NS_TO_US (HS_NSECS_ISO(bytes))

#define HS_USECS_ISO(bytes) NS_TO_US (HS_NSECS_ISO(bytes))