xhci: dbc: Don't use generic xhci inc_deq() function for dbc

The generic inc_deq() helper takes struct xhci_hcd pointer as a parameter,
and is a lot more complex than needed for the DbC usecase.

In order to decouple xhci and DbC we have to create our own small
inc_evt_deq() helper, not relying on xhci.

Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20200723144530.9992-3-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/host/xhci-dbgcap.c b/drivers/usb/host/xhci-dbgcap.c
index 987f893..424b571 100644 (file)
--- a/drivers/usb/host/xhci-dbgcap.c
+++ b/drivers/usb/host/xhci-dbgcap.c
@@ -644,6 +644,17 @@ static void dbc_handle_xfer_event(struct xhci_hcd *xhci, union xhci_trb *event)
        xhci_dbc_giveback(req, status);
 }
 
+static void inc_evt_deq(struct xhci_ring *ring)
+{
+       /* If on the last TRB of the segment go back to the beginning */
+       if (ring->dequeue == &ring->deq_seg->trbs[TRBS_PER_SEGMENT - 1]) {
+               ring->cycle_state ^= 1;
+               ring->dequeue = ring->deq_seg->trbs;
+               return;
+       }
+       ring->dequeue++;
+}
+
 static enum evtreturn xhci_dbc_do_handle_events(struct xhci_dbc *dbc)
 {
        dma_addr_t              deq;
@@ -765,7 +776,8 @@ static enum evtreturn xhci_dbc_do_handle_events(struct xhci_dbc *dbc)
                        break;
                }
 
-               inc_deq(xhci, dbc->ring_evt);
+               inc_evt_deq(dbc->ring_evt);
+
                evt = dbc->ring_evt->dequeue;
                update_erdp = true;
        }