+/*
+ * Finding the command trb need to be cancelled and modifying it to
+ * NO OP command. And if the command is in device's command wait
+ * list, finishing and freeing it.
+ *
+ * If we can't find the command trb, we think it had already been
+ * executed.
+ */
+static void xhci_cmd_to_noop(struct xhci_hcd *xhci, struct xhci_cd *cur_cd)
+{
+ struct xhci_segment *cur_seg;
+ union xhci_trb *cmd_trb;
+ u32 cycle_state;
+
+ if (xhci->cmd_ring->dequeue == xhci->cmd_ring->enqueue)
+ return;
+
+ /* find the current segment of command ring */
+ cur_seg = find_trb_seg(xhci->cmd_ring->first_seg,
+ xhci->cmd_ring->dequeue, &cycle_state);
+
+ if (!cur_seg) {
+ xhci_warn(xhci, "Command ring mismatch, dequeue = %p %llx (dma)\n",
+ xhci->cmd_ring->dequeue,
+ (unsigned long long)
+ xhci_trb_virt_to_dma(xhci->cmd_ring->deq_seg,
+ xhci->cmd_ring->dequeue));
+ xhci_debug_ring(xhci, xhci->cmd_ring);
+ xhci_dbg_ring_ptrs(xhci, xhci->cmd_ring);
+ return;
+ }
+
+ /* find the command trb matched by cd from command ring */
+ for (cmd_trb = xhci->cmd_ring->dequeue;
+ cmd_trb != xhci->cmd_ring->enqueue;
+ next_trb(xhci, xhci->cmd_ring, &cur_seg, &cmd_trb)) {
+ /* If the trb is link trb, continue */
+ if (TRB_TYPE_LINK_LE32(cmd_trb->generic.field[3]))
+ continue;
+
+ if (cur_cd->cmd_trb == cmd_trb) {
+
+ /* If the command in device's command list, we should
+ * finish it and free the command structure.
+ */
+ if (cur_cd->command)
+ xhci_complete_cmd_in_cmd_wait_list(xhci,
+ cur_cd->command, COMP_CMD_STOP);
+
+ /* get cycle state from the origin command trb */
+ cycle_state = le32_to_cpu(cmd_trb->generic.field[3])
+ & TRB_CYCLE;
+
+ /* modify the command trb to NO OP command */
+ cmd_trb->generic.field[0] = 0;
+ cmd_trb->generic.field[1] = 0;
+ cmd_trb->generic.field[2] = 0;
+ cmd_trb->generic.field[3] = cpu_to_le32(
+ TRB_TYPE(TRB_CMD_NOOP) | cycle_state);
+ break;
+ }
+ }
+}
+
+static void xhci_cancel_cmd_in_cd_list(struct xhci_hcd *xhci)
+{
+ struct xhci_cd *cur_cd, *next_cd;
+
+ if (list_empty(&xhci->cancel_cmd_list))
+ return;
+
+ list_for_each_entry_safe(cur_cd, next_cd,
+ &xhci->cancel_cmd_list, cancel_cmd_list) {
+ xhci_cmd_to_noop(xhci, cur_cd);
+ list_del(&cur_cd->cancel_cmd_list);
+ kfree(cur_cd);
+ }
+}
+
+/*
+ * traversing the cancel_cmd_list. If the command descriptor according
+ * to cmd_trb is found, the function free it and return 1, otherwise
+ * return 0.
+ */
+static int xhci_search_cmd_trb_in_cd_list(struct xhci_hcd *xhci,
+ union xhci_trb *cmd_trb)
+{
+ struct xhci_cd *cur_cd, *next_cd;
+
+ if (list_empty(&xhci->cancel_cmd_list))
+ return 0;
+
+ list_for_each_entry_safe(cur_cd, next_cd,
+ &xhci->cancel_cmd_list, cancel_cmd_list) {
+ if (cur_cd->cmd_trb == cmd_trb) {
+ if (cur_cd->command)
+ xhci_complete_cmd_in_cmd_wait_list(xhci,
+ cur_cd->command, COMP_CMD_STOP);
+ list_del(&cur_cd->cancel_cmd_list);
+ kfree(cur_cd);
+ return 1;
+ }
+ }
+
+ return 0;
+}
+
+/*
+ * If the cmd_trb_comp_code is COMP_CMD_ABORT, we just check whether the
+ * trb pointed by the command ring dequeue pointer is the trb we want to
+ * cancel or not. And if the cmd_trb_comp_code is COMP_CMD_STOP, we will
+ * traverse the cancel_cmd_list to trun the all of the commands according
+ * to command descriptor to NO-OP trb.
+ */
+static int handle_stopped_cmd_ring(struct xhci_hcd *xhci,
+ int cmd_trb_comp_code)
+{
+ int cur_trb_is_good = 0;
+
+ /* Searching the cmd trb pointed by the command ring dequeue
+ * pointer in command descriptor list. If it is found, free it.
+ */
+ cur_trb_is_good = xhci_search_cmd_trb_in_cd_list(xhci,
+ xhci->cmd_ring->dequeue);
+
+ if (cmd_trb_comp_code == COMP_CMD_ABORT)
+ xhci->cmd_ring_state = CMD_RING_STATE_STOPPED;
+ else if (cmd_trb_comp_code == COMP_CMD_STOP) {
+ /* traversing the cancel_cmd_list and canceling
+ * the command according to command descriptor
+ */
+ xhci_cancel_cmd_in_cd_list(xhci);
+
+ xhci->cmd_ring_state = CMD_RING_STATE_RUNNING;
+ /*
+ * ring command ring doorbell again to restart the
+ * command ring
+ */
+ if (xhci->cmd_ring->dequeue != xhci->cmd_ring->enqueue)
+ xhci_ring_cmd_db(xhci);
+ }
+ return cur_trb_is_good;
+}
+