From d3ac0778801708caecb2b172328064255a350432 Mon Sep 17 00:00:00 2001 From: Arjan Mels Date: Fri, 20 May 2011 23:25:46 +0200 Subject: [PATCH] staging: usbip: bugfix prevent driver unbind 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 Cc: Greg Kroah-Hartman Cc: Takahiro Hirofuchi Cc: Max Vozeler Cc: usbip-devel Signed-off-by: Greg Kroah-Hartman --- 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 6e99ec87fee0..8cbea42b69bc 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 a5c1fa1f0430..bc57844600b9 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; } -- 2.20.1