[PATCH 02/15] usb: xhci: add various debugging prints

[Ahmad Fatoum <a.fatoum@xxxxxxxxxxxxxx>]

For debugging potential issues around the driver, add some debug
prints.

Signed-off-by: Ahmad Fatoum <a.fatoum@xxxxxxxxxxxxxx>
---
 drivers/usb/host/xhci-ring.c |  8 ++++++++
 drivers/usb/host/xhci.c      | 16 +++++++++++++---
 2 files changed, 21 insertions(+), 3 deletions(-)

diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index 547047305dd0..804384e0307f 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -461,6 +461,14 @@ union xhci_trb *xhci_wait_for_event(struct xhci_ctrl *ctrl, trb_type expected,
 			BUG_ON(GET_COMP_CODE(
 				le32_to_cpu(event->generic.field[2])) !=
 								COMP_SUCCESS);
+		else
+			dev_dbg(ctrl->dev, "Unexpected XHCI event TRB, skipping... "
+				"(%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]));
+
 		xhci_acknowledge_event(ctrl);
 	} while (!is_timeout_non_interruptible(start, timeout_ms * MSECOND));
 
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index f149e784524d..01817d9c79cd 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -151,6 +151,8 @@ static int xhci_start(struct xhci_ctrl *ctrl)
 	u32 temp;
 	int ret;
 
+	dev_dbg(ctrl->dev, "Starting the controller\n");
+
 	temp = xhci_readl(&hcor->or_usbcmd);
 	temp |= (CMD_RUN);
 	xhci_writel(&hcor->or_usbcmd, temp);
@@ -1088,8 +1090,10 @@ static int xhci_submit_root(struct usb_device *udev, unsigned long pipe,
 static int _xhci_submit_int_msg(struct usb_device *udev, unsigned long pipe,
 				void *buffer, int length, int interval)
 {
-	if (usb_pipetype(pipe) != PIPE_INTERRUPT)
+	if (usb_pipetype(pipe) != PIPE_INTERRUPT) {
+		dev_err(&udev->dev, "non-interrupt pipe (type=%lu)", usb_pipetype(pipe));
 		return -EINVAL;
+	}
 
 	/*
 	 * xHCI uses normal TRBs for both bulk and interrupt. When the
@@ -1112,8 +1116,10 @@ static int _xhci_submit_int_msg(struct usb_device *udev, unsigned long pipe,
 static int _xhci_submit_bulk_msg(struct usb_device *udev, unsigned long pipe,
 				 void *buffer, int length, int timeout_ms)
 {
-	if (usb_pipetype(pipe) != PIPE_BULK)
+	if (usb_pipetype(pipe) != PIPE_BULK) {
+		dev_err(&udev->dev, "non-bulk pipe (type=%lu)", usb_pipetype(pipe));
 		return -EINVAL;
+	}
 
 	return xhci_bulk_tx(udev, pipe, length, buffer, timeout_ms);
 }
@@ -1137,8 +1143,10 @@ static int _xhci_submit_control_msg(struct usb_device *udev, unsigned long pipe,
 	struct xhci_ctrl *ctrl = xhci_get_ctrl(udev);
 	int ret = 0;
 
-	if (usb_pipetype(pipe) != PIPE_CONTROL)
+	if (usb_pipetype(pipe) != PIPE_CONTROL) {
+		dev_err(&udev->dev, "non-control pipe (type=%lu)", usb_pipetype(pipe));
 		return -EINVAL;
+	}
 
 	if (usb_pipedevice(pipe) == ctrl->rootdev)
 		return xhci_submit_root(udev, pipe, buffer, setup);
@@ -1218,6 +1226,8 @@ static int xhci_lowlevel_stop(struct xhci_ctrl *ctrl)
 
 	xhci_reset(ctrl);
 
+	dev_dbg(ctrl->dev, "Disabling event ring interrupts\n");
+
 	temp = xhci_readl(&ctrl->hcor->or_usbsts);
 	xhci_writel(&ctrl->hcor->or_usbsts, temp & ~STS_EINT);
 	temp = xhci_readl(&ctrl->ir_set->irq_pending);
-- 
2.39.2