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Commit 896fbd71 authored by Alan Stern's avatar Alan Stern Committed by Greg Kroah-Hartman
Browse files

usbcore: remove unused bandwith-related code 



This patch (as841) removes from usbcore a couple of support routines
meant to help with bandwidth allocation.  With the changes to uhci-hcd
in the previous patch, these routines are no longer used anywhere.
Also removed is the CONFIG_USB_BANDWIDTH option; it no longer does
anything and is no longer needed since the HCDs now handle bandwidth
issues correctly.

Signed-off-by: default avatarAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: default avatarDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 3ca2a321

drivers/usb/core/Kconfig

+0 −13
Original line number Diff line number Diff line
@@ -33,19 +33,6 @@ config USB_DEVICEFS 


	  Most users want to say Y here.



config USB_BANDWIDTH

	bool "Enforce USB bandwidth allocation (EXPERIMENTAL)"

	depends on USB && EXPERIMENTAL

	help

	  If you say Y here, the USB subsystem enforces USB bandwidth

	  allocation and will prevent some device opens from succeeding

	  if they would cause USB bandwidth usage to go above 90% of

	  the bus bandwidth.



	  If you say N here, these conditions will cause warning messages

	  about USB bandwidth usage to be logged and some devices or

	  drivers may not work correctly.



config USB_DYNAMIC_MINORS

	bool "Dynamic USB minor allocation (EXPERIMENTAL)"

	depends on USB && EXPERIMENTAL

drivers/usb/core/hcd.c

+0 −137
Original line number Diff line number Diff line
@@ -45,8 +45,6 @@ 
#include "hub.h"





// #define USB_BANDWIDTH_MESSAGES



/*-------------------------------------------------------------------------*/



/*
@@ -891,136 +889,6 @@ long usb_calc_bus_time (int speed, int is_input, int isoc, int bytecount) 
}

EXPORT_SYMBOL (usb_calc_bus_time);



/*

 * usb_check_bandwidth():

 *

 * old_alloc is from host_controller->bandwidth_allocated in microseconds;

 * bustime is from calc_bus_time(), but converted to microseconds.

 *

 * returns <bustime in us> if successful,

 * or -ENOSPC if bandwidth request fails.

 *

 * FIXME:

 * This initial implementation does not use Endpoint.bInterval

 * in managing bandwidth allocation.

 * It probably needs to be expanded to use Endpoint.bInterval.

 * This can be done as a later enhancement (correction).

 *

 * This will also probably require some kind of

 * frame allocation tracking...meaning, for example,

 * that if multiple drivers request interrupts every 10 USB frames,

 * they don't all have to be allocated at

 * frame numbers N, N+10, N+20, etc.  Some of them could be at

 * N+11, N+21, N+31, etc., and others at

 * N+12, N+22, N+32, etc.

 *

 * Similarly for isochronous transfers...

 *

 * Individual HCDs can schedule more directly ... this logic

 * is not correct for high speed transfers.

 */

int usb_check_bandwidth (struct usb_device *dev, struct urb *urb)

{

	unsigned int	pipe = urb->pipe;

	long		bustime;

	int		is_in = usb_pipein (pipe);

	int		is_iso = usb_pipeisoc (pipe);

	int		old_alloc = dev->bus->bandwidth_allocated;

	int		new_alloc;





	bustime = NS_TO_US (usb_calc_bus_time (dev->speed, is_in, is_iso,

			usb_maxpacket (dev, pipe, !is_in)));

	if (is_iso)

		bustime /= urb->number_of_packets;



	new_alloc = old_alloc + (int) bustime;

	if (new_alloc > FRAME_TIME_MAX_USECS_ALLOC) {

#ifdef	DEBUG

		char	*mode = 

#ifdef CONFIG_USB_BANDWIDTH

			"";

#else

			"would have ";

#endif

		dev_dbg (&dev->dev, "usb_check_bandwidth %sFAILED: %d + %ld = %d usec\n",

			mode, old_alloc, bustime, new_alloc);

#endif

#ifdef CONFIG_USB_BANDWIDTH

		bustime = -ENOSPC;	/* report error */

#endif

	}



	return bustime;

}

EXPORT_SYMBOL (usb_check_bandwidth);





/**

 * usb_claim_bandwidth - records bandwidth for a periodic transfer

 * @dev: source/target of request

 * @urb: request (urb->dev == dev)

 * @bustime: bandwidth consumed, in (average) microseconds per frame

 * @isoc: true iff the request is isochronous

 *

 * Bus bandwidth reservations are recorded purely for diagnostic purposes.

 * HCDs are expected not to overcommit periodic bandwidth, and to record such

 * reservations whenever endpoints are added to the periodic schedule.

 *

 * FIXME averaging per-frame is suboptimal.  Better to sum over the HCD's

 * entire periodic schedule ... 32 frames for OHCI, 1024 for UHCI, settable

 * for EHCI (256/512/1024 frames, default 1024) and have the bus expose how

 * large its periodic schedule is.

 */

void usb_claim_bandwidth (struct usb_device *dev, struct urb *urb, int bustime, int isoc)

{

	dev->bus->bandwidth_allocated += bustime;

	if (isoc)

		dev->bus->bandwidth_isoc_reqs++;

	else

		dev->bus->bandwidth_int_reqs++;

	urb->bandwidth = bustime;



#ifdef USB_BANDWIDTH_MESSAGES

	dev_dbg (&dev->dev, "bandwidth alloc increased by %d (%s) to %d for %d requesters\n",

		bustime,

		isoc ? "ISOC" : "INTR",

		dev->bus->bandwidth_allocated,

		dev->bus->bandwidth_int_reqs + dev->bus->bandwidth_isoc_reqs);

#endif

}

EXPORT_SYMBOL (usb_claim_bandwidth);





/**

 * usb_release_bandwidth - reverses effect of usb_claim_bandwidth()

 * @dev: source/target of request

 * @urb: request (urb->dev == dev)

 * @isoc: true iff the request is isochronous

 *

 * This records that previously allocated bandwidth has been released.

 * Bandwidth is released when endpoints are removed from the host controller's

 * periodic schedule.

 */

void usb_release_bandwidth (struct usb_device *dev, struct urb *urb, int isoc)

{

	dev->bus->bandwidth_allocated -= urb->bandwidth;

	if (isoc)

		dev->bus->bandwidth_isoc_reqs--;

	else

		dev->bus->bandwidth_int_reqs--;



#ifdef USB_BANDWIDTH_MESSAGES

	dev_dbg (&dev->dev, "bandwidth alloc reduced by %d (%s) to %d for %d requesters\n",

		urb->bandwidth,

		isoc ? "ISOC" : "INTR",

		dev->bus->bandwidth_allocated,

		dev->bus->bandwidth_int_reqs + dev->bus->bandwidth_isoc_reqs);

#endif

	urb->bandwidth = 0;

}

EXPORT_SYMBOL (usb_release_bandwidth);





/*-------------------------------------------------------------------------*/
@@ -1034,11 +902,6 @@ static void urb_unlink (struct urb *urb) 
{

	unsigned long		flags;



	/* Release any periodic transfer bandwidth */

	if (urb->bandwidth)

		usb_release_bandwidth (urb->dev, urb,

			usb_pipeisoc (urb->pipe));



	/* clear all state linking urb to this dev (and hcd) */



	spin_lock_irqsave (&hcd_data_lock, flags);

drivers/usb/core/hcd.h

+0 −6
Original line number Diff line number Diff line
@@ -308,10 +308,6 @@ extern void usb_destroy_configuration(struct usb_device *dev); 
#define NS_TO_US(ns)	((ns + 500L) / 1000L)

			/* convert & round nanoseconds to microseconds */



extern void usb_claim_bandwidth (struct usb_device *dev, struct urb *urb,

		int bustime, int isoc);

extern void usb_release_bandwidth (struct usb_device *dev, struct urb *urb,

		int isoc);



/*

 * Full/low speed bandwidth allocation constants/support.
@@ -324,8 +320,6 @@ extern void usb_release_bandwidth (struct usb_device *dev, struct urb *urb, 
#define FRAME_TIME_MAX_BITS_ALLOC	(90L * FRAME_TIME_BITS / 100L)

#define FRAME_TIME_MAX_USECS_ALLOC	(90L * FRAME_TIME_USECS / 100L)



extern int usb_check_bandwidth (struct usb_device *dev, struct urb *urb);



/*

 * 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

drivers/usb/core/urb.c

+0 −1
Original line number Diff line number Diff line
@@ -235,7 +235,6 @@ int usb_submit_urb(struct urb *urb, gfp_t mem_flags) 


	urb->status = -EINPROGRESS;

	urb->actual_length = 0;

	urb->bandwidth = 0;



	/* Lots of sanity checks, so HCDs can rely on clean data

	 * and don't need to duplicate tests

include/linux/usb.h

+0 −1
Original line number Diff line number Diff line
@@ -1110,7 +1110,6 @@ struct urb 
	struct kref kref;		/* reference count of the URB */

	spinlock_t lock;		/* lock for the URB */

	void *hcpriv;			/* private data for host controller */

	int bandwidth;			/* bandwidth for INT/ISO request */

	atomic_t use_count;		/* concurrent submissions counter */

	u8 reject;			/* submissions will fail */