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![]() This patch adds recovery from false busy state on concurrent attach operation. The procedure of attach operation is as below. 1) Find an unused port in /sys/devices/platform/vhci_hcd/status. (userspace) 2) Request attach found port to driver through /sys/devices/platform/vhci_hcd/attach. (userspace) 3) Lock table, reserve requested port and unlock table. (vhci driver) Attaching more than one remote devices concurrently, same unused port number will be found in step-1. Then one request will succeed and others will fail even though there are some unused ports. With this patch, driver returns EBUSY when requested port has already been used. In this case, attach command retries from step-1: finding another unused port. If there's no unused port, the attach operation will fail in step-1. Otherwise it retries automatically using another unused port. vhci-hcd's interface (only errno) is changed as following. Current errno New errno Condition EINVAL same as left specified port number is in invalid range EAGAIN same as left platform_get_drvdata() failed EINVAL same as left specified socket fd is not valid EINVAL EBUSY specified port status is not free The errno EBUSY was not used in userspace src/usbip_attach.c:import_device(). It is needed to distinguish the condition to be able to retry from other unrecoverable errors. It is possible to avoid this failure by introducing userspace exclusive control. But it's exaggerated for this special condition. The locking itself has done in driver. As an alternate solution, userspace doesn't specify port number, driver searches unused port and it returns port number to the userspace. With this solution, the interface is much different than this patch. Signed-off-by: Nobuo Iwata <nobuo.iwata@fujixerox.co.jp> Acked-by: Shuah Khan <shuahkh@osg.samsung.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
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README |
# # README for usbip-utils # # Copyright (C) 2011 matt mooney <mfm@muteddisk.com> # 2005-2008 Takahiro Hirofuchi [Overview] USB/IP protocol allows to pass USB device from server to client over the network. Server is a machine which provides (shares) a USB device. Client is a machine which uses USB device provided by server over the network. The USB device may be either physical device connected to a server or software entity created on a server using USB gadget subsystem. Whole project consists of four parts: - usbip-vhci A client side kernel module which provides a virtual USB Host Controller and allows to import a USB device from a remote machine. - usbip-host (stub driver) A server side module which provides a USB device driver which can be bound to a physical USB device to make it exportable. - usbip-vudc A server side module which provides a virtual USB Device Controller and allows to export a USB device created using USB Gadget Subsystem. - usbip-utils A set of userspace tools used to handle connection and management. Used on both sides. [Requirements] - USB/IP device drivers Found in the drivers/usb/usbip/ directory of the Linux kernel tree. - libudev >= 2.0 libudev library - libwrap0-dev tcp wrapper library - gcc >= 4.0 - libtool, automake >= 1.9, autoconf >= 2.5.0, pkg-config [Optional] - hwdata Contains USB device identification data. [Install] 0. Generate configuration scripts. $ ./autogen.sh 1. Compile & install the userspace utilities. $ ./configure [--with-tcp-wrappers=no] [--with-usbids-dir=<dir>] $ make install 2. Compile & install USB/IP drivers. [Usage] On a server side there are two entities which can be shared. First of them is physical usb device connected to the machine. To make it available below steps should be executed: server:# (Physically attach your USB device.) server:# insmod usbip-core.ko server:# insmod usbip-host.ko server:# usbipd -D - Start usbip daemon. server:# usbip list -l - List driver assignments for USB devices. server:# usbip bind --busid 1-2 - Bind usbip-host.ko to the device with busid 1-2. - The USB device 1-2 is now exportable to other hosts! - Use `usbip unbind --busid 1-2' to stop exporting the device. Second of shareable entities is USB Gadget created using USB Gadget Subsystem on a server machine. To make it available below steps should be executed: server:# (Create your USB gadget) - Currently the most preferable way of creating a new USB gadget is ConfigFS Composite Gadget. Please refer to its documentation for details. - See vudc_server_example.sh for a short example of USB gadget creation server:# insmod usbip-core.ko server:# insmod usbip-vudc.ko - To create more than one instance of vudc use num module param server:# (Bind gadget to one of available vudc) - Assign your new gadget to USB/IP UDC - Using ConfigFS interface you may do this simply by: server:# cd /sys/kernel/config/usb_gadget/<gadget_name> server:# echo "usbip-vudc.0" > UDC server:# usbipd -D --device - Start usbip daemon. To attach new device to client machine below commands should be used: client:# insmod usbip-core.ko client:# insmod vhci-hcd.ko client:# usbip list --remote <host> - List exported USB devices on the <host>. client:# usbip attach --remote <host> --busid 1-2 - Connect the remote USB device. - When using vudc on a server side busid is really vudc instance name. For example: usbip-vudc.0 client:# usbip port - Show virtual port status. client:# usbip detach --port <port> - Detach the USB device. [Example] --------------------------- SERVER SIDE --------------------------- Physically attach your USB devices to this host. trois:# insmod path/to/usbip-core.ko trois:# insmod path/to/usbip-host.ko trois:# usbipd -D In another terminal, let's look up what USB devices are physically attached to this host. trois:# usbip list -l Local USB devices ================= - busid 1-1 (05a9:a511) 1-1:1.0 -> ov511 - busid 3-2 (0711:0902) 3-2:1.0 -> none - busid 3-3.1 (08bb:2702) 3-3.1:1.0 -> snd-usb-audio 3-3.1:1.1 -> snd-usb-audio - busid 3-3.2 (04bb:0206) 3-3.2:1.0 -> usb-storage - busid 3-3 (0409:0058) 3-3:1.0 -> hub - busid 4-1 (046d:08b2) 4-1:1.0 -> none 4-1:1.1 -> none 4-1:1.2 -> none - busid 5-2 (058f:9254) 5-2:1.0 -> hub A USB storage device of busid 3-3.2 is now bound to the usb-storage driver. To export this device, we first mark the device as "exportable"; the device is bound to the usbip-host driver. Please remember you can not export a USB hub. Mark the device of busid 3-3.2 as exportable: trois:# usbip --debug bind --busid 3-3.2 ... usbip debug: usbip_bind.c:162:[unbind_other] 3-3.2:1.0 -> usb-storage ... bind device on busid 3-3.2: complete trois:# usbip list -l Local USB devices ================= ... - busid 3-3.2 (04bb:0206) 3-3.2:1.0 -> usbip-host ... --------------------------- CLIENT SIDE --------------------------- First, let's list available remote devices that are marked as exportable on the host. deux:# insmod path/to/usbip-core.ko deux:# insmod path/to/vhci-hcd.ko deux:# usbip list --remote 10.0.0.3 Exportable USB devices ====================== - 10.0.0.3 1-1: Prolific Technology, Inc. : unknown product (067b:3507) : /sys/devices/pci0000:00/0000:00:1f.2/usb1/1-1 : (Defined at Interface level) / unknown subclass / unknown protocol (00/00/00) : 0 - Mass Storage / SCSI / Bulk (Zip) (08/06/50) 1-2.2.1: Apple Computer, Inc. : unknown product (05ac:0203) : /sys/devices/pci0000:00/0000:00:1f.2/usb1/1-2/1-2.2/1-2.2.1 : (Defined at Interface level) / unknown subclass / unknown protocol (00/00/00) : 0 - Human Interface Devices / Boot Interface Subclass / Keyboard (03/01/01) 1-2.2.3: OmniVision Technologies, Inc. : OV511+ WebCam (05a9:a511) : /sys/devices/pci0000:00/0000:00:1f.2/usb1/1-2/1-2.2/1-2.2.3 : (Defined at Interface level) / unknown subclass / unknown protocol (00/00/00) : 0 - Vendor Specific Class / unknown subclass / unknown protocol (ff/00/00) 3-1: Logitech, Inc. : QuickCam Pro 4000 (046d:08b2) : /sys/devices/pci0000:00/0000:00:1e.0/0000:02:0a.0/usb3/3-1 : (Defined at Interface level) / unknown subclass / unknown protocol (00/00/00) : 0 - Data / unknown subclass / unknown protocol (0a/ff/00) : 1 - Audio / Control Device / unknown protocol (01/01/00) : 2 - Audio / Streaming / unknown protocol (01/02/00) Attach a remote USB device: deux:# usbip attach --remote 10.0.0.3 --busid 1-1 port 0 attached Show the devices attached to this client: deux:# usbip port Port 00: <Port in Use> at Full Speed(12Mbps) Prolific Technology, Inc. : unknown product (067b:3507) 6-1 -> usbip://10.0.0.3:3240/1-1 (remote bus/dev 001/004) 6-1:1.0 used by usb-storage /sys/class/scsi_device/0:0:0:0/device /sys/class/scsi_host/host0/device /sys/block/sda/device Detach the imported device: deux:# usbip detach --port 0 port 0 detached [Checklist] - See 'Debug Tips' on the project wiki. - http://usbip.wiki.sourceforge.net/how-to-debug-usbip - usbip-host.ko must be bound to the target device. - See /sys/kernel/debug/usb/devices and find "Driver=..." lines of the device. - Target USB gadget must be bound to vudc (using USB gadget susbsys, not usbip bind command) - Shutdown firewall. - usbip now uses TCP port 3240. - Disable SELinux. - Check the kernel and daemon messages. [Contact] Mailing List: linux-usb@vger.kernel.org