usb_claim_bandwidth(9)

NAME

usb_claim_bandwidth - records bandwidth for a periodic
transfer

SYNOPSIS

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

ARGUMENTS

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

DESCRIPTION

Bus bandwidth reservations are recorded purely for diag
nostic 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.

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