USB: usbtest: add a timeout for scatter-gather tests

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>

diff --git a/drivers/usb/misc/usbtest.c b/drivers/usb/misc/usbtest.c
index 4ed457e..71dcacb 100644 (file)
--- 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 vary)
        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 */