This patch contains usbip protocol documentation updates for
the implementation changes in subsequent patches.
Signed-off-by: Lars Gunnarsson <gunnarsson.lars@xxxxxxxxx>
---
v1: New patch added in series.
v2: Update paragraph according to review comments
Documentation/usb/usbip_protocol.rst | 61 ++++++++++++++++++++++++----
1 file changed, 53 insertions(+), 8 deletions(-)
diff --git a/Documentation/usb/usbip_protocol.rst b/Documentation/usb/usbip_protocol.rst
index 0b8541fda4d8..2d540fcc4b21 100644
--- a/Documentation/usb/usbip_protocol.rst
+++ b/Documentation/usb/usbip_protocol.rst
@@ -9,6 +9,11 @@ The USB/IP protocol follows a server/client architecture. The server exports the
USB devices and the clients import them. The device driver for the exported
USB device runs on the client machine.
+The server may choose to export any of its available USB devices based on their
+busid. These devices will remain exported until they are unplugged or unexported.
+Optionally, it is possible to persistently export the devices on a given bus by
+monitor when they are plugged in.
+
The client may ask for the list of the exported USB devices. To get the list the
client opens a TCP/IP connection to the server, and sends an OP_REQ_DEVLIST
packet on top of the TCP/IP connection (so the actual OP_REQ_DEVLIST may be sent
@@ -31,12 +36,7 @@ TCP/IP connection is closed.
Once the client knows the list of exported USB devices it may decide to use one
of them. First the client opens a TCP/IP connection to the server and
-sends an OP_REQ_IMPORT packet. The server replies with OP_REP_IMPORT. If the
-import was successful the TCP/IP connection remains open and will be used
-to transfer the URB traffic between the client and the server. The client may
-send two types of packets: the USBIP_CMD_SUBMIT to submit an URB, and
-USBIP_CMD_UNLINK to unlink a previously submitted URB. The answers of the
-server may be USBIP_RET_SUBMIT and USBIP_RET_UNLINK respectively.
+sends an OP_REQ_IMPORT packet. The server replies with OP_REP_IMPORT.
::
@@ -50,6 +50,47 @@ server may be USBIP_RET_SUBMIT and USBIP_RET_UNLINK respectively.
| OP_REP_IMPORT |
| <---------------------------------------------- |
| |
+
+The client may also request to poll for devices to become exported on a given
+busid, instead of immediately receive an error. If no device becomes exported
+within the chosen time, the server replies with timeout. The TCP/IP connection
+remains open and subsequent poll requests can be sent.
+
+::
+
+ virtual host controller usb host
+ "client" "server"
+ (imports USB devices) (exports USB devices)
+ | |
+ | OP_REQ_IMPORT |
+ | ----------------------------------------------> |
+ | . |
+ | : |
+ | |
+ | OP_REP_IMPORT |
+ | <---------------------------------------------- |
+ | |
+ | OP_REQ_IMPORT |
+ | ----------------------------------------------> |
+ | . |
+ | : |
+ | |
+ | OP_REP_IMPORT |
+ | <---------------------------------------------- |
+ | . |
+ | : |
+
+If the import was successful the TCP/IP connection remains open and will be used
+to transfer the URB traffic between the client and the server. The client may
+send two types of packets: the USBIP_CMD_SUBMIT to submit an URB, and
+USBIP_CMD_UNLINK to unlink a previously submitted URB. The answers of the
+server may be USBIP_RET_SUBMIT and USBIP_RET_UNLINK respectively.
+
+::
+
+ virtual host controller usb host
+ "client" "server"
+ (imports USB devices) (exports USB devices)
| |
| USBIP_CMD_SUBMIT(seqnum = n) |
| ----------------------------------------------> |
@@ -132,8 +173,8 @@ byte (MSB) is stored at the lowest address.
Protocol Version
================
-The documented USBIP version is v1.1.1. The binary representation of this
-version in message headers is 0x0111.
+The documented USBIP version is v1.1.2. The binary representation of this
+version in message headers is 0x0112.
This is defined in tools/usb/usbip/configure.ac
@@ -243,6 +284,10 @@ OP_REQ_IMPORT:
| | | | A string closed with zero, the unused bytes |
| | | | shall be filled with zeros. |
+-----------+--------+------------+---------------------------------------------------+
+| 40 | 4 | | poll timeout: instead of returning immediately if |
+| | | | device is not available, wait until usb device |
+| | | | becomes exported or a timeout occurs. |
++-----------+--------+------------+---------------------------------------------------+
OP_REP_IMPORT:
Reply to import (attach) a remote USB device.
--
2.25.1
