usb_alloc_urb(9) [suse man page]

USB_ALLOC_URB(9)						   USB Core APIs						  USB_ALLOC_URB(9)

NAME

       usb_alloc_urb - creates a new urb for a USB driver to use

SYNOPSIS

       struct urb * usb_alloc_urb(int iso_packets, gfp_t mem_flags);

ARGUMENTS

       iso_packets
	   number of iso packets for this urb

       mem_flags
	   the type of memory to allocate, see kmalloc for a list of valid options for this.

DESCRIPTION

       Creates an urb for the USB driver to use, initializes a few internal structures, incrementes the usage counter, and returns a pointer to
       it.

       If no memory is available, NULL is returned.

       If the driver want to use this urb for interrupt, control, or bulk endpoints, pass '0' as the number of iso packets.

       The driver must call usb_free_urb when it is finished with the urb.

COPYRIGHT

Kernel Hackers Manual 2.6.					     July 2010							  USB_ALLOC_URB(9)

USB_SG_INIT(9)							   USB Core APIs						    USB_SG_INIT(9)

NAME

       usb_sg_init - initializes scatterlist-based bulk/interrupt I/O request

SYNOPSIS

       int usb_sg_init(struct usb_sg_request * io, struct usb_device * dev, unsigned pipe, unsigned period, struct scatterlist * sg, int nents,
		       size_t length, gfp_t mem_flags);

ARGUMENTS

       io
	   request block being initialized. until usb_sg_wait returns, treat this as a pointer to an opaque block of memory,

       dev
	   the usb device that will send or receive the data

       pipe
	   endpoint "pipe" used to transfer the data

       period
	   polling rate for interrupt endpoints, in frames or (for high speed endpoints) microframes; ignored for bulk

       sg
	   scatterlist entries

       nents
	   how many entries in the scatterlist

       length
	   how many bytes to send from the scatterlist, or zero to send every byte identified in the list.

       mem_flags
	   SLAB_* flags affecting memory allocations in this call

DESCRIPTION

       Returns zero for success, else a negative errno value. This initializes a scatter/gather request, allocating resources such as I/O mappings
       and urb memory (except maybe memory used by USB controller drivers).

       The request must be issued using usb_sg_wait, which waits for the I/O to complete (or to be canceled) and then cleans up all resources
       allocated by usb_sg_init.

       The request may be canceled with usb_sg_cancel, either before or after usb_sg_wait is called.

COPYRIGHT

Kernel Hackers Manual 2.6.					     July 2010							    USB_SG_INIT(9)