[PATCH v15 16/50] usb: host: xhci-mem: Cleanup pending secondary event ring events

@@ -1827,7 +1827,7 @@ xhci_remove_interrupter(struct xhci_hcd *xhci, struct xhci_interrupter *ir)
 		tmp &= ERST_SIZE_MASK;
 		writel(tmp, &ir->ir_set->erst_size);
 
-		xhci_write_64(xhci, ERST_EHB, &ir->ir_set->erst_dequeue);
+		xhci_update_erst_dequeue(xhci, ir, true);
 	}
 }
 

@@ -1870,6 +1870,11 @@ void xhci_remove_secondary_interrupter(struct usb_hcd *hcd, struct xhci_interrup
 		return;
 	}
 
+	/*
+	 * Cleanup secondary interrupter to ensure there are no pending events.
+	 * This also updates event ring dequeue pointer back to the start.
+	 */
+	xhci_skip_sec_intr_events(xhci, ir->event_ring, ir);
 	intr_num = ir->intr_num;
 
 	xhci_remove_interrupter(xhci, ir);

@@ -2973,7 +2973,7 @@ static int xhci_handle_event_trb(struct xhci_hcd *xhci, struct xhci_interrupter
  * - When all events have finished
  * - To avoid "Event Ring Full Error" condition
  */
-static void xhci_update_erst_dequeue(struct xhci_hcd *xhci,
+void xhci_update_erst_dequeue(struct xhci_hcd *xhci,
 				     struct xhci_interrupter *ir,
 				     bool clear_ehb)
 {

@@ -3073,6 +3073,37 @@ static int xhci_handle_events(struct xhci_hcd *xhci, struct xhci_interrupter *ir
 	return 0;
 }
 
+/*
+ * Move the event ring dequeue pointer to skip events kept in the secondary
+ * event ring.  This is used to ensure that pending events in the ring are
+ * acknowledged, so the XHCI HCD can properly enter suspend/resume.  The
+ * secondary ring is typically maintained by an external component.
+ */
+void xhci_skip_sec_intr_events(struct xhci_hcd *xhci,
+	struct xhci_ring *ring,	struct xhci_interrupter *ir)
+{
+	union xhci_trb *current_trb;
+	u64 erdp_reg;
+	dma_addr_t deq;
+
+	/* disable irq, ack pending interrupt and ack all pending events */
+	xhci_disable_interrupter(ir);
+
+	/* last acked event trb is in erdp reg  */
+	erdp_reg = xhci_read_64(xhci, &ir->ir_set->erst_dequeue);
+	deq = (dma_addr_t)(erdp_reg & ERST_PTR_MASK);
+	if (!deq) {
+		xhci_err(xhci, "event ring handling not required\n");
+		return;
+	}
+
+	current_trb = ir->event_ring->dequeue;
+	/* read cycle state of the last acked trb to find out CCS */
+	ring->cycle_state = le32_to_cpu(current_trb->event_cmd.flags) & TRB_CYCLE;
+
+	xhci_handle_events(xhci, ir);
+}
+
 /*
  * xHCI spec says we can get an interrupt, and if the HC has an error condition,
  * we might get bad data out of the event ring.  Section 4.10.2.7 has a list of

@@ -1839,6 +1839,8 @@ struct xhci_interrupter *
 xhci_create_secondary_interrupter(struct usb_hcd *hcd, int num_seg);
 void xhci_remove_secondary_interrupter(struct usb_hcd
 				       *hcd, struct xhci_interrupter *ir);
+void xhci_skip_sec_intr_events(struct xhci_hcd *xhci,
+	struct xhci_ring *ring,	struct xhci_interrupter *ir);
 
 /* xHCI host controller glue */
 typedef void (*xhci_get_quirks_t)(struct device *, struct xhci_hcd *);

@@ -1930,6 +1932,9 @@ void inc_deq(struct xhci_hcd *xhci, struct xhci_ring *ring);
 unsigned int count_trbs(u64 addr, u64 len);
 int xhci_stop_endpoint_sync(struct xhci_hcd *xhci, struct xhci_virt_ep *ep,
 			    int suspend, gfp_t gfp_flags);
+void xhci_update_erst_dequeue(struct xhci_hcd *xhci,
+				     struct xhci_interrupter *ir,
+				     bool clear_ehb);
 
 /* xHCI roothub code */
 void xhci_set_link_state(struct xhci_hcd *xhci, struct xhci_port *port,