I tried connecting multiple usb 3.0 enabled devices to my ubuntu 12.04 machine. But found out that at a time not more than 9 devices could be seen connected. I tried monitoring the kernel logs at
/var/log/kern.log, where i found out that on connecting the 10th device, the below error was there:
this device cannot find enough free resources that it can use. (code 12)
My USB Host Controller is:
Intel Corporation 8 Series/C220 Series Chipset Family USB xHCI (rev 05)
Some forums have suggested disabling the USB 3.0 support should force the devices to work in USB 2.0 mode, and it should solve the problem. And this was true. Disabling xHCI support from BIOS did the trick for me.
I assumed this should be a bug on the older Ubuntu 12.04 setup(or the usb driver may be). Therefore, i upgraded my system to Ubuntu 16. But here also the same problem exists. What if i want to use my devices with USB 3.0? What if the option to disable xHCI support from BIOS is not present on some motherboard?