xhci: Remove recursive call to xhci_handle_event

Make the caller loop while there are events to handle, instead.

Signed-off-by: Matt Evans <matt@ozlabs.org>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>

1 files changed, 11 insertions, 7 deletions

diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index e0f05f5abe10..73f8db0ecc4b 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -2171,8 +2171,10 @@ cleanup:
 /*
  * This function handles all OS-owned events on the event ring.  It may drop
  * xhci->lock between event processing (e.g. to pass up port status changes).
+ * Returns >0 for "possibly more events to process" (caller should call again),
+ * otherwise 0 if done.  In future, <0 returns should indicate error code.
  */
-static void xhci_handle_event(struct xhci_hcd *xhci)
+static int xhci_handle_event(struct xhci_hcd *xhci)
 {
         union xhci_trb *event;
         int update_ptrs = 1;
@@ -2181,7 +2183,7 @@ static void xhci_handle_event(struct xhci_hcd *xhci)
         xhci_dbg(xhci, "In %s\n", __func__);
         if (!xhci->event_ring || !xhci->event_ring->dequeue) {
                 xhci->error_bitmask |= 1 << 1;
-                return;
+                return 0;
         }
 
         event = xhci->event_ring->dequeue;
@@ -2189,7 +2191,7 @@ static void xhci_handle_event(struct xhci_hcd *xhci)
         if ((le32_to_cpu(event->event_cmd.flags) & TRB_CYCLE) !=
             xhci->event_ring->cycle_state) {
                 xhci->error_bitmask |= 1 << 2;
-                return;
+                return 0;
         }
         xhci_dbg(xhci, "%s - OS owns TRB\n", __func__);
 
@@ -2233,15 +2235,17 @@ static void xhci_handle_event(struct xhci_hcd *xhci)
         if (xhci->xhc_state & XHCI_STATE_DYING) {
                 xhci_dbg(xhci, "xHCI host dying, returning from "
                                 "event handler.\n");
-                return;
+                return 0;
         }
 
         if (update_ptrs)
                 /* Update SW event ring dequeue pointer */
                 inc_deq(xhci, xhci->event_ring, true);
 
-        /* Are there more items on the event ring? */
-        xhci_handle_event(xhci);
+        /* Are there more items on the event ring?  Caller will call us again to
+         * check.
+         */
+        return 1;
 }
 
 /*
@@ -2323,7 +2327,7 @@ hw_died:
         /* FIXME this should be a delayed service routine
          * that clears the EHB.
          */
-        xhci_handle_event(xhci);
+        while (xhci_handle_event(xhci) > 0) {}
 
         temp_64 = xhci_read_64(xhci, &xhci->ir_set->erst_dequeue);
         /* If necessary, update the HW's version of the event ring deq ptr. */