[PATCH 3/4] docs: Fold usb2.txt physical port addressing info into usb.rst

[Peter Maydell]

Fold the usb2.txt documentation about specifying which physical
port a USB device should use into usb.rst.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 docs/system/devices/usb.rst | 33 +++++++++++++++++++++++++++++++++
 docs/usb2.txt               | 32 --------------------------------
 2 files changed, 33 insertions(+), 32 deletions(-)

diff --git a/docs/system/devices/usb.rst b/docs/system/devices/usb.rst
index 9f0e613dcc7..bab0cd3fdfd 100644
--- a/docs/system/devices/usb.rst
+++ b/docs/system/devices/usb.rst
@@ -199,6 +199,39 @@ option or the ``device_add`` monitor command. Available 
devices are:
 ``u2f-{emulated,passthru}``
    Universal Second Factor device
 
+Physical port addressing
+^^^^^^^^^^^^^^^^^^^^^^^^
+
+For all the above USB devices, by default QEMU will plug the device
+into the next available port on the specified USB bus, or onto
+some available USB bus if you didn't specify one explicitly.
+If you need to, you can also specify the physical port where
+the device will show up in the guest.  This can be done using the
+``port`` property.  UHCI has two root ports (1,2).  EHCI has six root
+ports (1-6), and the emulated (1.1) USB hub has eight ports.
+
+Plugging a tablet into UHCI port 1 works like this::
+
+        -device usb-tablet,bus=usb-bus.0,port=1
+
+Plugging a hub into UHCI port 2 works like this::
+
+        -device usb-hub,bus=usb-bus.0,port=2
+
+Plugging a virtual USB stick into port 4 of the hub just plugged works
+this way::
+
+        -device usb-storage,bus=usb-bus.0,port=2.4,drive=...
+
+In the monitor, the ``device_add` command also accepts a ``port``
+property specification. If you want to unplug devices too you should
+specify some unique id which you can use to refer to the device.
+You can then use ``device_del`` to unplug the device later.
+For example::
+
+        (qemu) device_add usb-tablet,bus=usb-bus.0,port=1,id=my-tablet
+        (qemu) device_del my-tablet
+
 Hotplugging USB storage
 ~~~~~~~~~~~~~~~~~~~~~~~
 
diff --git a/docs/usb2.txt b/docs/usb2.txt
index adf4ba3f2a0..6a88d5314f9 100644
--- a/docs/usb2.txt
+++ b/docs/usb2.txt
@@ -6,38 +6,6 @@ Recently the USB pass through driver (also known as usb-host) 
and the
 QEMU USB subsystem gained a few capabilities which are available only
 via qdev properties, i,e. when using '-device'.
 
-
-physical port addressing
-------------------------
-
-First you can (for all USB devices) specify the physical port where
-the device will show up in the guest.  This can be done using the
-"port" property.  UHCI has two root ports (1,2).  EHCI has six root
-ports (1-6), the emulated (1.1) USB hub has eight ports.
-
-Plugging a tablet into UHCI port 1 works like this:
-
-        -device usb-tablet,bus=usb-bus.0,port=1
-
-Plugging a hub into UHCI port 2 works like this:
-
-        -device usb-hub,bus=usb-bus.0,port=2
-
-Plugging a virtual USB stick into port 4 of the hub just plugged works
-this way:
-
-        -device usb-storage,bus=usb-bus.0,port=2.4,drive=...
-
-You can do basically the same in the monitor using the device_add
-command.  If you want to unplug devices too you should specify some
-unique id which you can use to refer to the device ...
-
-        (qemu) device_add usb-tablet,bus=usb-bus.0,port=1,id=my-tablet
-        (qemu) device_del my-tablet
-
-... when unplugging it with device_del.
-
-
 USB pass through hints
 ----------------------
 
-- 
2.20.1