[PATCH v7 3/5] usb: ehci-hcd: detect re-entrance

[Peter Mamonov]

Signed-off-by: Peter Mamonov <pmamonov at gmail.com>
---
 drivers/usb/host/ehci-hcd.c | 42 ++++++++++++++++++++++++++++++++++++++----
 1 file changed, 38 insertions(+), 4 deletions(-)

diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c
index 72f7414..c5f2dda 100644
--- a/drivers/usb/host/ehci-hcd.c
+++ b/drivers/usb/host/ehci-hcd.c
@@ -51,6 +51,8 @@ struct ehci_priv {
 	int periodic_schedules;
 	struct QH *periodic_queue;
 	uint32_t *periodic_list;
+	int sem;
+	struct device_d *usedby;
 };
 
 struct int_queue {
@@ -136,6 +138,20 @@ static struct descriptor {
 
 #define ehci_is_TDI()	(ehci->flags & EHCI_HAS_TT)
 
+static void inline ehci_reentrance_detect(struct ehci_priv *ehci,
+					  struct usb_device *dev,
+					  const char *fname)
+{
+	if (ehci->sem)
+		dev_err(&dev->dev, "%s: re-entrance %d (%s:%s)\n",
+			fname,
+			ehci->sem,
+			ehci->usedby->driver->name,
+			ehci->usedby->name);
+	ehci->sem++;
+	ehci->usedby = &dev->dev;
+}
+
 static int handshake(uint32_t *ptr, uint32_t mask, uint32_t done, int usec)
 {
 	uint32_t result;
@@ -893,12 +909,18 @@ submit_bulk_msg(struct usb_device *dev, unsigned long pipe, void *buffer,
 {
 	struct usb_host *host = dev->host;
 	struct ehci_priv *ehci = to_ehci(host);
+	int ret;
+
+	ehci_reentrance_detect(ehci, dev, __func__);
 
 	if (usb_pipetype(pipe) != PIPE_BULK) {
 		dev_dbg(ehci->dev, "non-bulk pipe (type=%lu)", usb_pipetype(pipe));
+		ehci->sem--;
 		return -1;
 	}
-	return ehci_submit_async(dev, pipe, buffer, length, NULL);
+	ret = ehci_submit_async(dev, pipe, buffer, length, NULL);
+	ehci->sem--;
+	return ret;
 }
 
 static int
@@ -907,6 +929,9 @@ submit_control_msg(struct usb_device *dev, unsigned long pipe, void *buffer,
 {
 	struct usb_host *host = dev->host;
 	struct ehci_priv *ehci = to_ehci(host);
+	int ret;
+
+	ehci_reentrance_detect(ehci, dev, __func__);
 
 	if (usb_pipetype(pipe) != PIPE_CONTROL) {
 		dev_dbg(ehci->dev, "non-control pipe (type=%lu)", usb_pipetype(pipe));
@@ -916,9 +941,13 @@ submit_control_msg(struct usb_device *dev, unsigned long pipe, void *buffer,
 	if (usb_pipedevice(pipe) == ehci->rootdev) {
 		if (ehci->rootdev == 0)
 			dev->speed = USB_SPEED_HIGH;
-		return ehci_submit_root(dev, pipe, buffer, length, setup);
+		ret = ehci_submit_root(dev, pipe, buffer, length, setup);
+		ehci->sem--;
+		return ret;
 	}
-	return ehci_submit_async(dev, pipe, buffer, length, setup);
+	ret = ehci_submit_async(dev, pipe, buffer, length, setup);
+	ehci->sem--;
+	return ret;
 }
 
 static int
@@ -1241,6 +1270,8 @@ submit_int_msg(struct usb_device *dev, unsigned long pipe, void *buffer,
 	void *backbuffer;
 	int result = 0, ret;
 
+	ehci_reentrance_detect(ehci, dev, __func__);
+
 	dev_dbg(ehci->dev, "dev=%p, pipe=%lu, buffer=%p, length=%d, interval=%d",
 	      dev, pipe, buffer, length, interval);
 
@@ -1248,8 +1279,10 @@ submit_int_msg(struct usb_device *dev, unsigned long pipe, void *buffer,
 				   DMA_BIDIRECTIONAL);
 
 	queue = ehci_create_int_queue(dev, pipe, 1, length, buffer, interval);
-	if (!queue)
+	if (!queue) {
+		ehci->sem--;
 		return -EINVAL;
+	}
 
 	start = get_time_ns();
 	while ((backbuffer = ehci_poll_int_queue(dev, queue)) == NULL)
@@ -1275,6 +1308,7 @@ submit_int_msg(struct usb_device *dev, unsigned long pipe, void *buffer,
 	ret = ehci_destroy_int_queue(dev, queue);
 	if (!result)
 		result = ret;
+	ehci->sem--;
 	return result;
 }
 
-- 
2.1.4