USB_STRING_IDS_N(9)                   Kernel Mode Gadget API                  USB_STRING_IDS_N(9)



NAME
       usb_string_ids_n - allocate unused string IDs in batch

SYNOPSIS
       int usb_string_ids_n(struct usb_composite_dev * c, unsigned n);

ARGUMENTS
       c
           the device whose string descriptor IDs are being allocated

       n
           number of string IDs to allocate

CONTEXT
       single threaded during gadget setup

DESCRIPTION
       Returns the first requested ID. This ID and next n-1 IDs are now valid IDs. At least
       provided that n is non-zero because if it is, returns last requested ID which is now very
       useful information.

       usb_string_ids_n() is called from bind callbacks to allocate string IDs. Drivers for
       functions, configurations, or gadgets will then store that ID in the appropriate
       descriptors and string table.

       All string identifier should be allocated using this, usb_string_id() or
       usb_string_ids_n() routine, to ensure that for example different functions don't wrongly
       assign different meanings to the same identifier.

AUTHOR
       David Brownell <dbrownell AT users.net>
           Author.

COPYRIGHT
Kernel Hackers Manual 4.8.                 January 2017                       USB_STRING_IDS_N(9)