Commit 498f78e6 authored by Dan Streetman's avatar Dan Streetman Committed by Linus Torvalds
Browse files

[PATCH] USB: fix in usb_calc_bus_time 



This patch does the same swap, i.e. use the ISO macro if (isoc).
Additionally, it fixes the return value - the usb_calc_bus_time function
returns the time in nanoseconds (I didn't notice that before) while the
HS_USECS and HS_USECS_ISO are microseconds.  This fixes the function to
return nanoseconds always, and adjusts ehci-q.c (the only high-speed
caller of the function) to wrap the call in NS_TO_US().

Signed-off-by: default avatarDan Streetman <ddstreet@ieee.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 6b216df8

drivers/usb/core/hcd.c

+2 −2
Original line number Diff line number Diff line
@@ -939,9 +939,9 @@ long usb_calc_bus_time (int speed, int is_input, int isoc, int bytecount) 
	case USB_SPEED_HIGH:	/* ISOC or INTR */

		// FIXME adjust for input vs output

		if (isoc)

			tmp = HS_USECS (bytecount);

			tmp = HS_NSECS_ISO (bytecount);

		else

			tmp = HS_USECS_ISO (bytecount);

			tmp = HS_NSECS (bytecount);

		return tmp;

	default:

		pr_debug ("%s: bogus device speed!\n", usbcore_name);

drivers/usb/core/hcd.h

+5 −3
Original line number Diff line number Diff line
@@ -334,17 +334,19 @@ extern void usb_release_bandwidth (struct usb_device *dev, struct urb *urb, 
extern int usb_check_bandwidth (struct usb_device *dev, struct urb *urb);



/*

 * Ceiling microseconds (typical) for that many bytes at high speed

 * Ceiling [nano/micro]seconds (typical) for that many bytes at high speed

 * ISO is a bit less, no ACK ... from USB 2.0 spec, 5.11.3 (and needed

 * to preallocate bandwidth)

 */

#define USB2_HOST_DELAY	5	/* nsec, guess */

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

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

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

	+ USB2_HOST_DELAY)

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

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

	+ ((2083UL * (3167 + 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))



extern long usb_calc_bus_time (int speed, int is_input,

			int isoc, int bytecount);

drivers/usb/host/ehci-q.c

+2 −2
Original line number Diff line number Diff line
@@ -657,8 +657,8 @@ qh_make ( 
	 * For control/bulk requests, the HC or TT handles these.

	 */

	if (type == PIPE_INTERRUPT) {

		qh->usecs = usb_calc_bus_time (USB_SPEED_HIGH, is_input, 0,

				hb_mult (maxp) * max_packet (maxp));

		qh->usecs = NS_TO_US (usb_calc_bus_time (USB_SPEED_HIGH, is_input, 0,

				hb_mult (maxp) * max_packet (maxp)));

		qh->start = NO_FRAME;



		if (urb->dev->speed == USB_SPEED_HIGH) {

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