I, like many others have problems with connecting many USB devices that has many endpoints with the dreaded dmesg message
usb 1-2.1.4: Not enough host controller resources for new device state.
usb 1-2.1.4: can't set config #1, error -12
I’ve read many posts where @DaneLLL among others states that there is a hardware limitation. But I seem to hit this limit with only 17 endpoints, and others seem to have much more endpoints.
So, my question is, what is the hardware limitation and where can I read about it? And also, what can I do about it if all my endpoints come from a single device (that uses an internal hub to connect 4 modems that each has 6 endpoints)
I can’t answer, but sometimes that message is just misleading. It could indeed be because you have too many devices relative to what the Jetson can handle, but sometimes it is also due to needing too much bandwidth. As an example, and isochronous mode camera or audio device reserves a certain amount of bandwidth and guarantees a maximum latency; if you have two such cameras, and they are both isochronous, then they might need to reserve more bandwidth than is available. Similar cameras, using the same bandwidth, but working in a bulk transfer mode, won’t have that issue in quite the same way. Those bulk mode cameras might miss a frame here and there, but they can operate with delay and with for bandwidth (e.g., between frames of the other camera), and they won’t outright fail.
The number of devices is probably important in the question, and I cannot answer that, but the type of devices and the type of transfer mode is also relevant.