[PATCH v2 8/8] usb: xhci: Add more debugging

[Hector Martin]

A bunch of miscellaneous debug messages to aid in working out USB
issues.

Signed-off-by: Hector Martin <marcan at marcan.st>
---
 drivers/usb/host/xhci-ring.c | 29 ++++++++++++++++++++++++++---
 1 file changed, 26 insertions(+), 3 deletions(-)

diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index b60661fe05e7..dabe6cf86af2 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -214,6 +214,9 @@ static dma_addr_t queue_trb(struct xhci_ctrl *ctrl, struct xhci_ring *ring,
 
 	addr = xhci_trb_virt_to_dma(ring->enq_seg, (union xhci_trb *)trb);
 
+	debug("trb @ %llx: %08x %08x %08x %08x\n", addr,
+	      trb_fields[0], trb_fields[1], trb_fields[2], trb_fields[3]);
+
 	inc_enq(ctrl, ring, more_trbs_coming);
 
 	return addr;
@@ -296,6 +299,8 @@ void xhci_queue_command(struct xhci_ctrl *ctrl, dma_addr_t addr, u32 slot_id,
 {
 	u32 fields[4];
 
+	debug("CMD: %llx 0x%x 0x%x %d\n", addr, slot_id, ep_index, cmd);
+
 	BUG_ON(prepare_ring(ctrl, ctrl->cmd_ring, EP_STATE_RUNNING));
 
 	fields[0] = lower_32_bits(addr);
@@ -471,8 +476,14 @@ union xhci_trb *xhci_wait_for_event(struct xhci_ctrl *ctrl, trb_type expected)
 
 		type = TRB_FIELD_TO_TYPE(le32_to_cpu(event->event_cmd.flags));
 		if (type == expected ||
-		    (expected == TRB_NONE && type != TRB_PORT_STATUS))
+		    (expected == TRB_NONE && type != TRB_PORT_STATUS)) {
+			debug("Event: %08x %08x %08x %08x\n",
+			      le32_to_cpu(event->generic.field[0]),
+			      le32_to_cpu(event->generic.field[1]),
+			      le32_to_cpu(event->generic.field[2]),
+			      le32_to_cpu(event->generic.field[3]));
 			return event;
+		}
 
 		if (type == TRB_PORT_STATUS)
 		/* TODO: remove this once enumeration has been reworked */
@@ -484,8 +495,9 @@ union xhci_trb *xhci_wait_for_event(struct xhci_ctrl *ctrl, trb_type expected)
 				le32_to_cpu(event->generic.field[2])) !=
 								COMP_SUCCESS);
 		else
-			printf("Unexpected XHCI event TRB, skipping... "
+			printf("Unexpected XHCI event TRB, expected %d... "
 				"(%08x %08x %08x %08x)\n",
+				expected,
 				le32_to_cpu(event->generic.field[0]),
 				le32_to_cpu(event->generic.field[1]),
 				le32_to_cpu(event->generic.field[2]),
@@ -602,10 +614,13 @@ static void abort_td(struct usb_device *udev, int ep_index)
 static void record_transfer_result(struct usb_device *udev,
 				   union xhci_trb *event, int length)
 {
+	xhci_comp_code code = GET_COMP_CODE(
+		le32_to_cpu(event->trans_event.transfer_len));
+
 	udev->act_len = min(length, length -
 		(int)EVENT_TRB_LEN(le32_to_cpu(event->trans_event.transfer_len)));
 
-	switch (GET_COMP_CODE(le32_to_cpu(event->trans_event.transfer_len))) {
+	switch (code) {
 	case COMP_SUCCESS:
 		BUG_ON(udev->act_len != length);
 		/* fallthrough */
@@ -613,16 +628,23 @@ static void record_transfer_result(struct usb_device *udev,
 		udev->status = 0;
 		break;
 	case COMP_STALL:
+		debug("Xfer STALL\n");
 		udev->status = USB_ST_STALLED;
 		break;
 	case COMP_DB_ERR:
+		debug("Xfer DB_ERR\n");
+		udev->status = USB_ST_BUF_ERR;
+		break;
 	case COMP_TRB_ERR:
+		debug("Xfer TRB_ERR\n");
 		udev->status = USB_ST_BUF_ERR;
 		break;
 	case COMP_BABBLE:
+		debug("Xfer BABBLE\n");
 		udev->status = USB_ST_BABBLE_DET;
 		break;
 	default:
+		debug("Xfer error: %d\n", code);
 		udev->status = 0x80;  /* USB_ST_TOO_LAZY_TO_MAKE_A_NEW_MACRO */
 	}
 }
@@ -1016,6 +1038,7 @@ int xhci_ctrl_tx(struct usb_device *udev, unsigned long pipe,
 	record_transfer_result(udev, event, length);
 	xhci_acknowledge_event(ctrl);
 	if (udev->status == USB_ST_STALLED) {
+		debug("EP %d stalled\n", ep_index);
 		reset_ep(udev, ep_index);
 		return -EPIPE;
 	}

-- 
2.41.0