The event_ring_deq parameter is used to check if the event ring dequeue
position is updated while calling by xhci_handle_event(), meaning there was
an actual event on the ring to handle. In this case the driver needs to
inform hardware about the updated dequeue position.
Basically event_ring_deq just stores the old event ring dequeue position
before calling the event handler.

Keeping track of software event dequeue updates this way is no longer
useful as driver anyways reads the current hardware dequeue position
within the handle event, and checks if it needs to be updated.

The driver might anyway need to modify the EHB (event handler busy) bit in
the same register as the dequeue pointer even if the actual dequeue
position did not change.
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
Link: https://lore.kernel.org/r/20240217001017.29969-5-quic_wcheng@quicinc.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>