[PATCH 3.14 015/110] USB: usbtest: add a timeout for scatter-gather tests

Greg Kroah-Hartman
2014-06-28T17:49:05Z

From: Alan Stern <stern@rowland.harvard.edu>

commit 32b36eeae6a859670d2939a7d6136cb5e9ed64f8 upstream.

In usbtest, tests 5 - 8 use the scatter-gather library in usbcore
without any sort of timeout. If there's a problem in the gadget or
host controller being tested, the test can hang.

This patch adds a 10-second timeout to the tests, so that they will
fail gracefully with an ETIMEDOUT error instead of hanging.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Reported-by: Huang Rui <ray.huang@amd.com>
Tested-by: Huang Rui <ray.huang@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/usb/misc/usbtest.c | 16 +++++++++++++++-
1 file changed, 15 insertions(+), 1 deletion(-)

--- a/drivers/usb/misc/usbtest.c
+++ b/drivers/usb/misc/usbtest.c
@@ -7,7 +7,7 @@
#include <linux/moduleparam.h>
#include <linux/scatterlist.h>
#include <linux/mutex.h>
-
+#include <linux/timer.h>
#include <linux/usb.h>

#define SIMPLE_IO_TIMEOUT 10000 /* in milliseconds */
@@ -484,6 +484,14 @@ alloc_sglist(int nents, int max, int var
return sg;
}

+static void sg_timeout(unsigned long _req)
+{
+ struct usb_sg_request *req = (struct usb_sg_request *) _req;
+
+ req->status = -ETIMEDOUT;
+ usb_sg_cancel(req);
+}
+
static int perform_sglist(
struct usbtest_dev *tdev,
unsigned iterations,
@@ -495,6 +503,9 @@ static int perform_sglist(
{
struct usb_device *udev = testdev_to_usbdev(tdev);
int retval = 0;
+ struct timer_list sg_timer;
+
+ setup_timer_on_stack(&sg_timer, sg_timeout, (unsigned long) req);

while (retval == 0 && iterations-- > 0) {
retval = usb_sg_init(req, udev, pipe,
@@ -505,7 +516,10 @@ static int perform_sglist(

if (retval)
break;
+ mod_timer(&sg_timer, jiffies +
+ msecs_to_jiffies(SIMPLE_IO_TIMEOUT));
usb_sg_wait(req);
+ del_timer_sync(&sg_timer);
retval = req->status;

/* FIXME check resulting data pattern */