1USB_EP_FIFO_STATUS(9)       Kernel Mode Gadget API       USB_EP_FIFO_STATUS(9)
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NAME

6       usb_ep_fifo_status - returns number of bytes in fifo, or error
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SYNOPSIS

9       int usb_ep_fifo_status(struct usb_ep * ep);
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ARGUMENTS

12       ep
13           the endpoint whose fifo status is being checked.
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DESCRIPTION

16       FIFO endpoints may have “unclaimed data” in them in certain cases, such
17       as after aborted transfers. Hosts may not have collected all the IN
18       data written by the gadget driver (and reported by a request
19       completion). The gadget driver may not have collected all the data
20       written OUT to it by the host. Drivers that need precise handling for
21       fault reporting or recovery may need to use this call.
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23       This returns the number of such bytes in the fifo, or a negative errno
24       if the endpoint doesn't use a FIFO or doesn't support such precise
25       handling.
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AUTHOR

28       David Brownell <dbrownell@users.sourceforge.net>
29           Author.
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32Kernel Hackers Manual 3.10         June 2019             USB_EP_FIFO_STATUS(9)
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