Question Older USB2 webcam in a 3.2 Gen2 port

[modex20]

As far as I understand, this should be no issue since USB gens are always backwards compatible. But I had some strange initial behavior when plugging it in for the first time and I’m wondering what happened.

The board is a MSI B450 TOMAHAWK MAX with the latest BIOS running on and up to date fresh install of Win10 with the AMD chipset drivers (from AMD’s site not MSI). Legacy USB and XHCI modes are both enabled (by default). I have the keyboard and mouse in the rear USB2 ports. Then I have a headset dongle and Razer Tartarus in the two rear USB3.2 Gen1 slots. No issues up to that point.

Recently, I tried hooking up an old Microsoft LifeCam. The only remaining rear port was the USB3.2 Gen2 slot. So, with the pc running idle in windows, I plugged it in. Windows did the usual detected hardware routine. When it was done and said the device was ready, I went to a simple webcam test site in chrome. Chrome asked for permission to use the camera but the page still couldn’t detect it. I looked in device manager and saw there was an unknown usb device (device descriptor request failed) despite the fact that windows gave me the notification that it had set up the device.

I tried a restart of windows. But got a black screen with a cursor. I am not sure if the restart finished and this was a pre POST problem or if the restart process froze. I did a CTRL ALT DEL and the system POSTed then booted into windows. Initially I had no use of the keyboard or mouse. After a minute, they came online. But I got a windows notification that a usb device is malfunctioning. I still had the unknown device in device manager and the camera still didn’t work.

I then unplugged the camera. The unknown device went away as expected. Then I plugged it into one of the front USB2 ports on my case. Windows detected the device and set it up again. This time there was no unknown device in device manager and the webcam test worked. Out of curiosity, I unplugged the camera from the front and plugged it back into the rear USB3.2 Gen2 port. It still worked and there was still no unknown device in device manager. I restarted windows and it booted up fine. Camera still works.

Any idea why it got all wonky the first time and why temporarily plugging it into a 2.0 port seemed to fix it?

 

[Insert_Nickname]

Odd. Tried using usbdview to uninstall the webcam?

USB is not known as UnStableBus for nothing.

 

[modex20]

Just tried it. Reinstalls no problem if I plug it back into the Gen2 port. My guess is some driver got downloaded once it finally got what it needed from the device descriptor. Good that it works now but kinda sucks that I can't reproduce it and determine the root cause.

 

[Insert_Nickname]

Good to hear it works.

Good that it works now but kinda sucks that I can't reproduce it and determine the root cause.

Don't think too much about it. Windows has issues with USB devices from time to time. I'm not sure anybody outside MS can figure out why.

 

[Paperdoc]

My GUESS is that, first time around, Windows found a new device plugged into the USB3 Gen2 port and went looking for a suitable driver for such devices. Having installed that it made inquiries to confirm and found the actual device plugged in was not as expected, and gave up trying to figure that out. Later when you plugged it into the front USB2 port it could not make that type of mistake and found the correct driver for the camera. Thereafter when you moved it back to the UBB3 Gen 2 port it HAD the correct driver already and merely had to note the change of port for the onnection to that device.