Hi Gerd > Subject: Re: [PATCH v6 1/8] hw/usb/bus: Let a bus opt out of automatic hub > insertion > > On Mon, Oct 19, 2026 at 09:24:50AM +0000, Jamin Lin wrote: > > usb_claim_port() inserts a usb-hub when a device is plugged in and > > only one port is still free, so that more devices can follow. That is > > what a host controller with root ports wants. > > Ah, well, not really. It's there mostly for historical reasons. > > The emulated usb hub supports only usb 1.1, so for newer host controllers > (ehci > / xhci) it does not make much sense and the better approach is to add more > host controllers if needed. Which should rarely actually be the case though > given that xhci supports up to 15 root ports. > > So if this gets into the way I'm wondering whenever the better approach here > is to remove this altogether. You can still add an USB hub manually of > needed, > IIRC there is (or was?) some board with a single-port OHCI where you actually > need a hub if you want plug in both usb keyboard and usb mouse. It just > would not be automatic any more. > > Alternative idea would be to add the config option, but only enable the > automatic hub logic for actual usb 1.1 controllers (ohci / uhci), where it > does > not matter much for devices whenever they are plugged into an root port or > hub port. > > take care, > Gerd
Sorry for the late reply. Yes, it gets in the way. usbredir carries one device per connection, so our bus has one port. Plugging that device in adds a hub, and the device ends up behind it. That is why I added the flag. If you would rather do one of these, tell me and I will send it: 1. Remove the automatic hub. 2. Keep it, but only for the USB 1.1 controllers, ohci and uhci. Thanks, Jamin
