Stop generating traffic for a given endpoint when a transfer reported

an I/O error.

When such thing happens, the device is more likely to be already gone
or non responding, but the task responsible for aborting the pipe has
not been executed.

Fix a problem where the ehci(4) controller would vomit^Wprint a lot of
"ehci_idone:" messages in loop leaving the machine unusable, initially
reported by ajacoutot@ and later by RD Thrush.

Fix tested by RD Thrush and Markus Bergkvist, thanks!

ok miod@

1 files changed, 17 insertions, 8 deletions

diff --git a/sys/dev/usb/usbdi.c b/sys/dev/usb/usbdi.c
index 8e515a16c69..768bdbdbbb6 100644
--- a/sys/dev/usb/usbdi.c
+++ b/sys/dev/usb/usbdi.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: usbdi.c,v 1.59 2013/09/20 15:34:51 mpi Exp $ */
+/*	$OpenBSD: usbdi.c,v 1.60 2013/09/24 09:01:41 mpi Exp $ */
 /*	$NetBSD: usbdi.c,v 1.103 2002/09/27 15:37:38 provos Exp $	*/
 /*	$FreeBSD: src/sys/dev/usb/usbdi.c,v 1.28 1999/11/17 22:33:49 n_hibma Exp $	*/
 
@@ -731,7 +731,6 @@ usb_transfer_complete(struct usbd_xfer *xfer)
 {
 	struct usbd_pipe *pipe = xfer->pipe;
 	struct usb_dma *dmap = &xfer->dmabuf;
-	int repeat = pipe->repeat;
 	int polling;
 
 	SPLUSBCHECK;
@@ -771,14 +770,14 @@ usb_transfer_complete(struct usbd_xfer *xfer)
 
 	/* if we allocated the buffer in usbd_transfer() we free it here. */
 	if (xfer->rqflags & URQ_AUTO_DMABUF) {
-		if (!repeat) {
+		if (!pipe->repeat) {
 			struct usbd_bus *bus = pipe->device->bus;
 			usb_freemem(bus, dmap);
 			xfer->rqflags &= ~URQ_AUTO_DMABUF;
 		}
 	}
 
-	if (!repeat) {
+	if (!pipe->repeat) {
 		/* Remove request from queue. */
 #ifdef DIAGNOSTIC
 		if (xfer != SIMPLEQ_FIRST(&pipe->queue))
@@ -788,8 +787,8 @@ usb_transfer_complete(struct usbd_xfer *xfer)
 #endif
 		SIMPLEQ_REMOVE_HEAD(&pipe->queue, next);
 	}
-	DPRINTFN(5,("usb_transfer_complete: repeat=%d new head=%p\n", repeat,
-	    SIMPLEQ_FIRST(&pipe->queue)));
+	DPRINTFN(5,("usb_transfer_complete: repeat=%d new head=%p\n",
+	    pipe->repeat, SIMPLEQ_FIRST(&pipe->queue)));
 
 	/* Count completed transfers. */
 	++pipe->device->bus->stats.uds_requests
@@ -803,7 +802,16 @@ usb_transfer_complete(struct usbd_xfer *xfer)
 		xfer->status = USBD_SHORT_XFER;
 	}
 
-	if (repeat) {
+	if (pipe->repeat) {
+		/*
+		 * If we already got an I/O error that generally means
+		 * the device is gone or not responding, so don't try
+		 * to enqueue a new transfer as it will more likely
+		 * results in the same error.
+		 */
+		if (xfer->status == USBD_IOERROR)
+			pipe->repeat = 0;
+
 		if (xfer->callback)
 			xfer->callback(xfer, xfer->priv, xfer->status);
 		pipe->methods->done(xfer);
@@ -816,9 +824,10 @@ usb_transfer_complete(struct usbd_xfer *xfer)
 	if ((xfer->flags & USBD_SYNCHRONOUS) && !polling)
 		wakeup(xfer);
 
-	if (!repeat) {
+	if (!pipe->repeat) {
 		/* XXX should we stop the queue on all errors? */
 		if ((xfer->status == USBD_CANCELLED ||
+		     xfer->status == USBD_IOERROR ||
 		     xfer->status == USBD_TIMEOUT) &&
 		    pipe->iface != NULL)		/* not control pipe */
 			pipe->running = 0;