[PATCH v13 09/53] xhci: add helper that checks for unhandled events on a event ring

Wesley Cheng
2024-02-03T02:37:48Z

From: Mathias Nyman <mathias.nyman@linux.intel.com>

Add unhandled_event_trb() that returns true in case xHC hardware has
written new event trbs to the event ring that driver has not yet handled.

Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
---
drivers/usb/host/xhci-ring.c | 11 ++++++++---
1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index 338b6fddedc3..48388bc16b24 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -113,6 +113,12 @@ static bool last_td_in_urb(struct xhci_td *td)
return urb_priv->num_tds_done == urb_priv->num_tds;
}

+static bool unhandled_event_trb(struct xhci_ring *ring)
+{
+ return ((le32_to_cpu(ring->dequeue->event_cmd.flags) & TRB_CYCLE) ==
+ ring->cycle_state);
+}
+
static void inc_td_cnt(struct urb *urb)
{
struct urb_priv *urb_priv = urb->hcpriv;
@@ -2923,9 +2929,8 @@ static int xhci_handle_event(struct xhci_hcd *xhci, struct xhci_interrupter *ir)
}

event = ir->event_ring->dequeue;
- /* Does the HC or OS own the TRB? */
- if ((le32_to_cpu(event->event_cmd.flags) & TRB_CYCLE) !=
- ir->event_ring->cycle_state)
+
+ if (!unhandled_event_trb(ir->event_ring))
return 0;

trace_xhci_handle_event(ir->event_ring, &event->generic);