Better USB error handling: move "pending_writes" check earlier.

git-svn-id: http://svn.digium.com/svn/zaptel/trunk@1407 5390a7c7-147a-4af0-8ec9-7488f05a26cb

1 files changed, 16 insertions, 12 deletions

diff --git a/xpp/xpp_usb.c b/xpp/xpp_usb.c
index 605ddd8..89571c3 100644
--- a/xpp/xpp_usb.c
+++ b/xpp/xpp_usb.c
@@ -292,7 +292,18 @@ static int xusb_packet_send(xbus_t *xbus, xpacket_t *pack)
 	if(!xusb->present) {
 		NOTICE("tried to send packets to non-exitant USB device. Ignored\n");
 		ret = -ENODEV;
-		goto out;
+		goto freepack;
+	}
+	/*
+	 * If something really bad happend, do not overflow the USB stack
+	 */
+	if(atomic_read(&xusb->pending_writes) > MAX_PENDING_WRITES) {
+		static	int rate_limit;
+
+		if((rate_limit++ % 1000) < 10)
+			ERR("%s: %s: more than %d pending writes. Dropping.\n", __FUNCTION__, xbus->busname, MAX_PENDING_WRITES);
+		ret = -ENODEV;
+		goto freepack;
 	}
 	size = PACKET_LEN(pack);
 	xusb_ep = &xusb->endpoints[XUSB_SEND];
@@ -300,7 +311,7 @@ static int xusb_packet_send(xbus_t *xbus, xpacket_t *pack)
 	if (!urb) {
 		ERR("No free urbs available\n");
 		ret = -ENOMEM;
-		goto out;
+		goto freepack;
 	}
 	packet_debug("USB_PACKET_SEND", xusb, pack);
 
@@ -315,22 +326,15 @@ static int xusb_packet_send(xbus_t *xbus, xpacket_t *pack)
 			ERR("%s: failed submit_urb: %d\n", __FUNCTION__, ret);
 		xpp_urb_delete(urb);
 		ret = -EBADF;
-		goto out;
+		goto freepack;
 	}
 	atomic_inc(&xusb->pending_writes);
-	if(atomic_read(&xusb->pending_writes) > MAX_PENDING_WRITES) {
-		static	int rate_limit;
-
-		if((rate_limit++ % 1000) < 10)
-			ERR("%s: %s: more than %d pending writes. Dropping.\n", __FUNCTION__, xbus->busname, MAX_PENDING_WRITES);
-		ret = -ENODEV;
-	}
 	if(pack->content.opcode == XPROTO_NAME(GLOBAL,PCM_WRITE))
 		XUSB_COUNTER(xusb, PCM_WRITES)++;
-out:
+freepack:
+	xbus->ops->packet_free(xbus, pack);	// FIXME: eventually will be done in the urb callback
 	if(ret < 0)
 		XUSB_COUNTER(xusb, TX_ERRORS)++;
-	xbus->ops->packet_free(xbus, pack);	// FIXME: eventually will be done in the urb callback
 	return ret;
 }