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.         June 2019           USB_HCD_CHECK_UNLINK(9)
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