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usbcore: remove unused bandwith-related code
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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: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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Alan Stern authored and Greg Kroah-Hartman committed Feb 7, 2007
1 parent 3ca2a32 commit 896fbd7
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13 changes: 0 additions & 13 deletions drivers/usb/core/Kconfig
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Original file line number Diff line number Diff line change
Expand Up @@ -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
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137 changes: 0 additions & 137 deletions drivers/usb/core/hcd.c
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Original file line number Diff line number Diff line change
Expand Up @@ -45,8 +45,6 @@
#include "hub.h"


// #define USB_BANDWIDTH_MESSAGES

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

/*
Expand Down Expand Up @@ -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);


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

Expand All @@ -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);
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6 changes: 0 additions & 6 deletions drivers/usb/core/hcd.h
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Original file line number Diff line number Diff line change
Expand Up @@ -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.
Expand All @@ -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
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1 change: 0 additions & 1 deletion drivers/usb/core/urb.c
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Original file line number Diff line number Diff line change
Expand Up @@ -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
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1 change: 0 additions & 1 deletion include/linux/usb.h
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Original file line number Diff line number Diff line change
Expand Up @@ -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 */

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