1USB_HCD_CHECK_UNLINK(9)      Host Controller APIs      USB_HCD_CHECK_UNLINK(9)
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NAME

6       usb_hcd_check_unlink_urb - check whether an URB may be unlinked
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SYNOPSIS

9       int usb_hcd_check_unlink_urb(struct usb_hcd * hcd, struct urb * urb,
10                                    int status);
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ARGUMENTS

13       hcd
14           host controller to which urb was submitted
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16       urb
17           URB being checked for unlinkability
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19       status
20           error code to store in urb if the unlink succeeds
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DESCRIPTION

23       Host controller drivers should call this routine in their dequeue
24       method. The HCD's private spinlock must be held and interrupts must be
25       disabled. The actions carried out here are required for making sure
26       than an unlink is valid.
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28       Returns 0 for no error, otherwise a negative error code (in which case
29       the dequeue method must fail). The possible error codes are:
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31       -EIDRM: urb was not submitted or has already completed. The completion
32       function may not have been called yet.
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34       -EBUSY: urb has already been unlinked.
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37Kernel Hackers Manual 2.6.       November 2011         USB_HCD_CHECK_UNLINK(9)
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