Hi,
This is 10,000 foot question for a issue I am looking at :
Quite a few servers have a BCM that expose a USB keyboard and mouse when a " iLo client session " is started that also provides a remote console.
For instance on Bus 01.Port 1: Dev 1, Port 8 there are these devices :
lsusb -t
/: Bus 02.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/10p, 5000M
/: Bus 01.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/16p, 480M
|__ Port 8: Dev 2, If 0, Class=Hub, Driver=hub/7p, 480M
|__ Port 3: Dev 3, If 0, Class=Communications, Driver=cdc_ether, 480M
|__ Port 3: Dev 3, If 1, Class=CDC Data, Driver=cdc_ether, 480M
When a remote viewer ( iLO ) session is started, two HID appear under Port 8 :
lsusb -t
/: Bus 02.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/10p, 5000M
/: Bus 01.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/16p, 480M
|__ Port 8: Dev 2, If 0, Class=Hub, Driver=hub/7p, 480M
|__ Port 1: Dev 7, If 0, Class=Human Interface Device, Driver=usbhid,480M
|__ Port 2: Dev 6, If 0, Class=Human Interface Device, Driver=usbhid,480M
|__ Port 3: Dev 3, If 0, Class=Communications, Driver=cdc_ether, 480M
|__ Port 3: Dev 3, If 1, Class=CDC Data, Driver=cdc_ether, 480M
Is this device tree showing me the Port 8 is somehow wired to the BCM ? And the BCM did some sort of operation that causes the xhci_hcd driver to enumerate a new device ?
The driver : “ usbhid “ in real life appears to be a built-in component to the kernel - Not a loadable module . I suspect that is so keyboards always work.
When the iLO session is terminated the two HID devices disappear .
If anyone can point me documentation how this works I would appreciate it.
Thank you for your time.
JD
