usb: dwc3: add tracepoints to aid debugging

When we're debugging hard-to-reproduce and time-sensitive
use cases, printk() poses too much overhead. That's when
the kernel's tracing infrastructure comes into play.

This patch implements a few initial tracepoints for the
dwc3 driver. More traces can be added as necessary in order
to ease the task of debugging dwc3.

Reviewed-by: Paul Zimmerman <paulz@synopsys.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

1 files changed, 15 insertions, 21 deletions

diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 096b63838dc..f2dbaca5df2 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -267,6 +267,7 @@ void dwc3_gadget_giveback(struct dwc3_ep *dep, struct dwc3_request *req,
 	dev_dbg(dwc->dev, "request %p from %s completed %d/%d ===> %d\n",
 			req, dep->name, req->request.actual,
 			req->request.length, status);
+	trace_dwc3_gadget_giveback(req);
 
 	spin_unlock(&dwc->lock);
 	req->request.complete(&dep->endpoint, &req->request);
@@ -278,8 +279,7 @@ int dwc3_send_gadget_generic_command(struct dwc3 *dwc, unsigned cmd, u32 param)
 	u32		timeout = 500;
 	u32		reg;
 
-	dev_vdbg(dwc->dev, "generic cmd '%s' [%d] param %08x\n",
-			dwc3_gadget_generic_cmd_string(cmd), cmd, param);
+	trace_dwc3_gadget_generic_cmd(cmd, param);
 
 	dwc3_writel(dwc->regs, DWC3_DGCMDPAR, param);
 	dwc3_writel(dwc->regs, DWC3_DGCMD, cmd | DWC3_DGCMD_CMDACT);
@@ -310,10 +310,7 @@ int dwc3_send_gadget_ep_cmd(struct dwc3 *dwc, unsigned ep,
 	u32			timeout = 500;
 	u32			reg;
 
-	dev_vdbg(dwc->dev, "%s: cmd '%s' [%d] params %08x %08x %08x\n",
-			dep->name,
-			dwc3_gadget_ep_cmd_string(cmd), cmd, params->param0,
-			params->param1, params->param2);
+	trace_dwc3_gadget_ep_cmd(dep, cmd, params);
 
 	dwc3_writel(dwc->regs, DWC3_DEPCMDPAR0(ep), params->param0);
 	dwc3_writel(dwc->regs, DWC3_DEPCMDPAR1(ep), params->param1);
@@ -710,6 +707,8 @@ static struct usb_request *dwc3_gadget_ep_alloc_request(struct usb_ep *ep,
 	req->epnum	= dep->number;
 	req->dep	= dep;
 
+	trace_dwc3_alloc_request(req);
+
 	return &req->request;
 }
 
@@ -718,6 +717,7 @@ static void dwc3_gadget_ep_free_request(struct usb_ep *ep,
 {
 	struct dwc3_request		*req = to_dwc3_request(request);
 
+	trace_dwc3_free_request(req);
 	kfree(req);
 }
 
@@ -799,6 +799,8 @@ static void dwc3_prepare_one_trb(struct dwc3_ep *dep,
 		trb->ctrl |= DWC3_TRB_CTRL_SID_SOFN(req->request.stream_id);
 
 	trb->ctrl |= DWC3_TRB_CTRL_HWO;
+
+	trace_dwc3_prepare_trb(dep, trb);
 }
 
 /*
@@ -1143,6 +1145,7 @@ static int dwc3_gadget_ep_queue(struct usb_ep *ep, struct usb_request *request,
 
 	dev_vdbg(dwc->dev, "queing request %p to %s length %d\n",
 			request, ep->name, request->length);
+	trace_dwc3_ep_queue(req);
 
 	spin_lock_irqsave(&dwc->lock, flags);
 	ret = __dwc3_gadget_ep_queue(dep, req);
@@ -1163,6 +1166,8 @@ static int dwc3_gadget_ep_dequeue(struct usb_ep *ep,
 	unsigned long			flags;
 	int				ret = 0;
 
+	trace_dwc3_ep_dequeue(req);
+
 	spin_lock_irqsave(&dwc->lock, flags);
 
 	list_for_each_entry(r, &dep->request_list, list) {
@@ -1753,6 +1758,8 @@ static int __dwc3_cleanup_done_trbs(struct dwc3 *dwc, struct dwc3_ep *dep,
 	unsigned int		s_pkt = 0;
 	unsigned int		trb_status;
 
+	trace_dwc3_complete_trb(dep, trb);
+
 	if ((trb->ctrl & DWC3_TRB_CTRL_HWO) && status != -ESHUTDOWN)
 		/*
 		 * We continue despite the error. There is not much we
@@ -1927,9 +1934,6 @@ static void dwc3_endpoint_interrupt(struct dwc3 *dwc,
 	if (!(dep->flags & DWC3_EP_ENABLED))
 		return;
 
-	dev_vdbg(dwc->dev, "%s: %s\n", dep->name,
-			dwc3_ep_event_string(event->endpoint_event));
-
 	if (epnum == 0 || epnum == 1) {
 		dwc3_ep0_interrupt(dwc, event);
 		return;
@@ -2122,8 +2126,6 @@ static void dwc3_gadget_disconnect_interrupt(struct dwc3 *dwc)
 {
 	int			reg;
 
-	dev_vdbg(dwc->dev, "%s\n", __func__);
-
 	reg = dwc3_readl(dwc->regs, DWC3_DCTL);
 	reg &= ~DWC3_DCTL_INITU1ENA;
 	dwc3_writel(dwc->regs, DWC3_DCTL, reg);
@@ -2142,8 +2144,6 @@ static void dwc3_gadget_reset_interrupt(struct dwc3 *dwc)
 {
 	u32			reg;
 
-	dev_vdbg(dwc->dev, "%s\n", __func__);
-
 	/*
 	 * WORKAROUND: DWC3 revisions <1.88a have an issue which
 	 * would cause a missing Disconnect Event if there's a
@@ -2228,8 +2228,6 @@ static void dwc3_gadget_conndone_interrupt(struct dwc3 *dwc)
 	u32			reg;
 	u8			speed;
 
-	dev_vdbg(dwc->dev, "%s\n", __func__);
-
 	reg = dwc3_readl(dwc->regs, DWC3_DSTS);
 	speed = reg & DWC3_DSTS_CONNECTSPD;
 	dwc->speed = speed;
@@ -2327,8 +2325,6 @@ static void dwc3_gadget_conndone_interrupt(struct dwc3 *dwc)
 
 static void dwc3_gadget_wakeup_interrupt(struct dwc3 *dwc)
 {
-	dev_vdbg(dwc->dev, "%s\n", __func__);
-
 	/*
 	 * TODO take core out of low power mode when that's
 	 * implemented.
@@ -2433,10 +2429,6 @@ static void dwc3_gadget_linksts_change_interrupt(struct dwc3 *dwc,
 		break;
 	}
 
-	dev_vdbg(dwc->dev, "link change: %s [%d] -> %s [%d]\n",
-			dwc3_gadget_link_string(dwc->link_state),
-			dwc->link_state, dwc3_gadget_link_string(next), next);
-
 	dwc->link_state = next;
 }
 
@@ -2513,6 +2505,8 @@ static void dwc3_gadget_interrupt(struct dwc3 *dwc,
 static void dwc3_process_event_entry(struct dwc3 *dwc,
 		const union dwc3_event *event)
 {
+	trace_dwc3_event(event->raw);
+
 	/* Endpoint IRQ, handle it and return early */
 	if (event->type.is_devspec == 0) {
 		/* depevt */