1USB_EP_FIFO_STATUS(9) Kernel Mode Gadget API USB_EP_FIFO_STATUS(9)
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6 usb_ep_fifo_status - returns number of bytes in fifo, or error
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9 int usb_ep_fifo_status(struct usb_ep * ep);
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12 ep
13 the endpoint whose fifo status is being checked.
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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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28 David Brownell <dbrownell@users.sourceforge.net>
29 Author.
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32Kernel Hackers Manual 2.6. June 2019 USB_EP_FIFO_STATUS(9)