USB device is enumerated correctly, but I never see a Setup transaction with bRequest equal to SET_ADDRESS

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Summary:
While capturing USB traffic with wireshark, I see that devices enumerate properly when plugged in, but I never see the USB address getting assigned by the host.

Details:
I have tried this on both Windows 10 and Linux, and on several types of USB devices.
I plug in a device, and capture the USB traffic using Wireshark. I expect to see a Setup transaction, with the data packet containing bRequest = 0x05 (SET_ADDRESS) and the wValue word containing the address to be assigned. But I never see this. The wireshark capture does show the other traffic I expect, like "GET DESCRIPTOR" request and response for the device, but no SET_ADDRESS. The simplest device I have is a USB 1.1 mouse, and the wireshark capture (summary lines only) is below.

No.     Time           Source                Destination           Protocol Length Info
  1 0.000000       1.1.1                 host                  USB      66     URB_INTERRUPT in
  2 0.000013       host                  1.1.1                 USB      64     URB_INTERRUPT in
  3 0.000029       host                  1.1.0                 USBHUB   64     GET_STATUS Request     [Port 7]
  4 0.000040       1.1.0                 host                  USBHUB   68     GET_STATUS Response    [Port 7]
  5 0.000093       host                  1.1.0                 USBHUB   64     CLEAR_FEATURE Request  [Port 7: C_PORT_CONNECTION]
  6 0.000102       1.1.0                 host                  USBHUB   64     CLEAR_FEATURE Response [Port 7: C_PORT_CONNECTION]
  7 0.000107       host                  1.1.0                 USBHUB   64     GET_STATUS Request     [Port 7]
  8 0.000111       1.1.0                 host                  USBHUB   68     GET_STATUS Response    [Port 7]
  9 0.025302       host                  1.1.0                 USBHUB   64     GET_STATUS Request     [Port 7]
 10 0.025316       1.1.0                 host                  USBHUB   68     GET_STATUS Response    [Port 7]
 11 0.051308       host                  1.1.0                 USBHUB   64     GET_STATUS Request     [Port 7]
 12 0.051322       1.1.0                 host                  USBHUB   68     GET_STATUS Response    [Port 7]
 13 0.077299       host                  1.1.0                 USBHUB   64     GET_STATUS Request     [Port 7]
 14 0.077313       1.1.0                 host                  USBHUB   68     GET_STATUS Response    [Port 7]
 15 0.103306       host                  1.1.0                 USBHUB   64     GET_STATUS Request     [Port 7]
 16 0.103319       1.1.0                 host                  USBHUB   68     GET_STATUS Response    [Port 7]
 17 0.103370       host                  1.1.0                 USBHUB   64     SET_FEATURE Request    [Port 7: PORT_RESET]
 18 0.103377       1.1.0                 host                  USBHUB   64     SET_FEATURE Response   [Port 7: PORT_RESET]
 19 0.154307       host                  1.1.0                 USBHUB   64     GET_STATUS Request     [Port 7]
 20 0.154321       1.1.0                 host                  USBHUB   68     GET_STATUS Response    [Port 7]
 21 0.205298       host                  1.1.0                 USBHUB   64     GET_STATUS Request     [Port 7]
 22 0.205312       1.1.0                 host                  USBHUB   68     GET_STATUS Response    [Port 7]
 23 0.205319       host                  1.1.0                 USBHUB   64     CLEAR_FEATURE Request  [Port 7: C_PORT_RESET]
 24 0.205324       1.1.0                 host                  USBHUB   64     CLEAR_FEATURE Response [Port 7: C_PORT_RESET]
 25 0.256351       host                  1.0.0                 USB      64     GET DESCRIPTOR Request DEVICE
 26 0.257055       1.0.0                 host                  USB      82     GET DESCRIPTOR Response DEVICE
 27 0.257095       host                  1.1.0                 USBHUB   64     SET_FEATURE Request    [Port 7: PORT_RESET]
 28 0.257108       1.1.0                 host                  USBHUB   64     SET_FEATURE Response   [Port 7: PORT_RESET]
 29 0.307248       host                  1.1.0                 USBHUB   64     GET_STATUS Request     [Port 7]
 30 0.307259       1.1.0                 host                  USBHUB   68     GET_STATUS Response    [Port 7]
 31 0.358299       host                  1.1.0                 USBHUB   64     GET_STATUS Request     [Port 7]
 32 0.358313       1.1.0                 host                  USBHUB   68     GET_STATUS Response    [Port 7]
 33 0.358319       host                  1.1.0                 USBHUB   64     CLEAR_FEATURE Request  [Port 7: C_PORT_RESET]
 34 0.358325       1.1.0                 host                  USBHUB   64     CLEAR_FEATURE Response [Port 7: C_PORT_RESET]
 35 0.420304       host                  1.49.0                USB      64     GET DESCRIPTOR Request DEVICE
 36 0.421084       1.49.0                host                  USB      82     GET DESCRIPTOR Response DEVICE
 37 0.421113       host                  1.49.0                USB      64     GET DESCRIPTOR Request CONFIGURATION
 38 0.421678       1.49.0                host                  USB      73     GET DESCRIPTOR Response CONFIGURATION
 39 0.421696       host                  1.49.0                USB      64     GET DESCRIPTOR Request CONFIGURATION
 40 0.422754       1.49.0                host                  USB      98     GET DESCRIPTOR Response CONFIGURATION
 41 0.422773       host                  1.49.0                USB      64     GET DESCRIPTOR Request STRING
 42 0.423173       1.49.0                host                  USB      68     GET DESCRIPTOR Response STRING
 43 0.423189       host                  1.49.0                USB      64     GET DESCRIPTOR Request STRING
 44 0.424279       1.49.0                host                  USB      100    GET DESCRIPTOR Response STRING
 45 0.424297       host                  1.49.0                USB      64     GET DESCRIPTOR Request STRING
 46 0.424955       1.49.0                host                  USB      78     GET DESCRIPTOR Response STRING
 47 0.425460       host                  1.49.0                USB      64     SET CONFIGURATION Request
 48 0.425747       1.49.0                host                  USB      64     SET CONFIGURATION Response
 49 0.425778       host                  1.49.0                USB      64     GET DESCRIPTOR Request STRING
 50 0.426997       1.49.0                host                  USB      104    GET DESCRIPTOR Response STRING
 51 0.427139       host                  1.49.0                USBHID   64     SET_IDLE Request
 52 0.427345       1.49.0                host                  USBHID   64     SET_IDLE Response
 53 0.427389       host                  1.49.0                USBHID   64     GET DESCRIPTOR Request HID Report
 54 0.428913       1.49.0                host                  USBHID   116    GET DESCRIPTOR Response HID Report
 55 0.429551       host                  1.49.1                USB      64     URB_INTERRUPT in
 56 0.487331       1.49.1                host                  USB      64     URB_INTERRUPT in
 57 0.496308       host                  1.49.1                USB      64     URB_INTERRUPT in

As expected, the host is communicating with the hub (at bus1, address 1), and then suddenly in transaction 35, the host can communicate with the device at address 49 which is the mouse. (I verified this by looking in the response, captured in transaction 36, which contains the idVendor and idProduct for the mouse.)
Every document I've seen so far says that the device address is assigned by the host, using a Setup Transaction of type SET_ADDRESS. And yet there is none here. Also, the address 49 (0x31) does not appear in any packets preceding the use of the address in transaction 35.

This same behavior is seen on both Windows 10 and Linux. It is seen on various devices: a mouse, a TI development board, and a USB headset. All of the devices enumerate, and are usable, and end up with reasonable USB addresses.

I don't understand how the device gets its USB address. What am I missing?

Background: Someone always asks "Why do you want to do this?". I am writing embedded code for a TI processor that supports USB. I am debugging some of the traffic, and at one point I decided to go back to basics, and trace through the entire startup sequence. The SET_ADDRESS was missing, and I then found that it is missing on other devices, too. I'd like to know why. Perhaps other transactions/packets are missing, as well?

usb
1 Answers

After more searching and experimenting, I have an answer.

The Short Answer: Wireshark cannot show the USB address assignment transaction because it is not captured by the lower-level libraries used by wireshark.

The Full Story: For some reason, it seems that the USB libraries used by wireshark do not capture the address assignment. The Windows version of these libraries, usbpcap, acknowledges this and other limitations on the web page. I did not find a similar disclaimer for the Linux version, but I suspect that the same technical limitations would affect both versions, and that's why I did not see the address assignment in wireshark on either Windows or Linux.

To verify that the USB device enumeration was working even though not captured by wireshark, I programed a USB device on a TI ARM development board which had pins on the D+ and D- USB signal lines. I attached a logic analyzer and captured the enumeration sequence. The result was exactly as described in every USB tutorial. Here is the part of the enumeration sequence where the device address is assigned: enter image description here After the token packet (with Setup Packet ID, still using address 0, endpoint 0), the Setup packet with a DATA0 PID contains in its payload the expected bRequest byte 0x05 (SET_ADDRESS) followed by the low byte of wValue, equal in this example to 0x26, the assigned address. Don't forget when looking at captures like this that the least significant bytes and bits come first. So to make sense of each byte, you need to flip the bit stream byte-by-byte before converting to the hex values. So 01100100b becomes 0010 0110 or 0x26.

user_24039140
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