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[PATCH] USB: fix in usb_calc_bus_time
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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: Dan Streetman <ddstreet@ieee.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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Dan Streetman authored and Linus Torvalds committed Jul 29, 2005
1 parent 6b216df commit 498f78e
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Showing 3 changed files with 9 additions and 7 deletions.
4 changes: 2 additions & 2 deletions drivers/usb/core/hcd.c
Original file line number Diff line number Diff line change
Expand Up @@ -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);
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8 changes: 5 additions & 3 deletions drivers/usb/core/hcd.h
Original file line number Diff line number Diff line change
Expand Up @@ -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);
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4 changes: 2 additions & 2 deletions drivers/usb/host/ehci-q.c
Original file line number Diff line number Diff line change
Expand Up @@ -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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