From: Arjan Mels <arjan.mels@xxxxxxx>
Implemented pre_reset and post_reset methods of the driver to prevent the
driver from being unbound upon a device reset. Because of this also the
asynchronous reset introduced to prevent a race condition is no longer necessary
(and sometimes causes problems, because it comes later then expected).
Signed-off-by: Arjan Mels <arjan.mels@xxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxx>
Cc: Takahiro Hirofuchi <hirofuchi@xxxxxxxxxxxxxxxxxxxxx>
Cc: Max Vozeler <max@xxxxxxxxxxx>
Cc: usbip-devel <usbip-devel@xxxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>
---
drivers/staging/usbip/stub_dev.c | 21 +++++++++++++++++++++
drivers/staging/usbip/stub_rx.c | 20 +++++++++++---------
2 files changed, 32 insertions(+), 9 deletions(-)
diff --git a/drivers/staging/usbip/stub_dev.c b/drivers/staging/usbip/stub_dev.c
index 6e99ec8..8cbea42 100644
--- a/drivers/staging/usbip/stub_dev.c
+++ b/drivers/staging/usbip/stub_dev.c
@@ -26,6 +26,8 @@
static int stub_probe(struct usb_interface *interface,
const struct usb_device_id *id);
static void stub_disconnect(struct usb_interface *interface);
+static int stub_pre_reset(struct usb_interface *interface);
+static int stub_post_reset(struct usb_interface *interface);
/*
* Define device IDs here if you want to explicitly limit exportable devices.
@@ -59,6 +61,8 @@ struct usb_driver stub_driver = {
.probe = stub_probe,
.disconnect = stub_disconnect,
.id_table = stub_table,
+ .pre_reset = stub_pre_reset,
+ .post_reset = stub_post_reset,
};
/*
@@ -541,3 +545,20 @@ static void stub_disconnect(struct usb_interface *interface)
del_match_busid((char *)udev_busid);
}
}
+
+/*
+ * Presence of pre_reset and post_reset prevents the driver from being unbound
+ * when the device is being reset
+ */
+
+int stub_pre_reset(struct usb_interface *interface)
+{
+ dev_dbg(&interface->dev, "pre_reset\n");
+ return 0;
+}
+
+int stub_post_reset(struct usb_interface *interface)
+{
+ dev_dbg(&interface->dev, "post_reset\n");
+ return 0;
+}
diff --git a/drivers/staging/usbip/stub_rx.c b/drivers/staging/usbip/stub_rx.c
index a5c1fa1..bc57844 100644
--- a/drivers/staging/usbip/stub_rx.c
+++ b/drivers/staging/usbip/stub_rx.c
@@ -175,16 +175,18 @@ static int tweak_reset_device_cmd(struct urb *urb)
dev_info(&urb->dev->dev, "usb_queue_reset_device\n");
/*
- * usb_lock_device_for_reset caused a deadlock: it causes the driver
- * to unbind. In the shutdown the rx thread is signalled to shut down
- * but this thread is pending in the usb_lock_device_for_reset.
- *
- * Instead queue the reset.
- *
- * Unfortunatly an existing usbip connection will be dropped due to
- * driver unbinding.
+ * With the implementation of pre_reset and post_reset the driver no
+ * longer unbinds. This allows the use of synchronous reset.
*/
- usb_queue_reset_device(sdev->interface);
+
+ if (usb_lock_device_for_reset(sdev->udev, sdev->interface)<0)
+ {
+ dev_err(&urb->dev->dev, "could not obtain lock to reset device\n");
+ return 0;
+ }
+ usb_reset_device(sdev->udev);
+ usb_unlock_device(sdev->udev);
+
return 0;
}
--
1.7.5.4
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