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staging: usbip: bugfix prevent driver unbind

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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@gmx.net>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Cc: Takahiro Hirofuchi <hirofuchi@users.sourceforge.net>
Cc: Max Vozeler <max@vozeler.com>
Cc: usbip-devel <usbip-devel@lists.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Arjan Mels 2011-05-20 23:25:46 +02:00 committed by Greg Kroah-Hartman
parent c11c4eebdd
commit d3ac077880
2 changed files with 32 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

21
drivers/staging/usbip/stub_dev.c
View File

@ -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;
}

20
drivers/staging/usbip/stub_rx.c
View File

@ -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;
}