+ a picoscope 5244B
+ a laptop runing Ubuntu 12.04 LTS
kernel 3.8.0-35-generic x86_64 GNU/Linux
00:14.0 USB controller: Intel Corporation 7 Series/C210 Series Chipset Family USB xHCI Host Controller (rev 04)
00:1a.0 USB controller: Intel Corporation 7 Series/C210 Series Chipset Family USB Enhanced Host Controller #2 (rev 04)
00:1d.0 USB controller: Intel Corporation 7 Series/C210 Series Chipset Family USB Enhanced Host Controller #1(rev 04)
Every time I plug the picoscope to the USB port the LED turns red and it is listed in the lsusb output. Then, when I start the picoscope software and it tries to connect the scope, the LED flashes green twice or three times producing a "commuting relay" sound but suddently it turns OFF and no data is acquired. The application continues running with no means to reconnect scope unless it is unplugged physically from the USB port and plugged back. Again, LED is red and the process is repeated.
Looking on the dmesg, it reports a reset
... reset high speed usb device using xhci_hcd
On other laptop it runs OK with an ehci_hcd driver.
Are Enhanced Host Controller and ehcd equivalent? Can I use them? How? Currently, there are no ehci_hcd entries on /sys/bus/pci/drivers . There is an entry called ehci-pci and the xhci_hcd.
The solution I've seen is to recompile kernel with xhci and ehci as modules. Then, blacklist the xhci driver and bind the ehci_hcd driver. Could it work? Is there any other simpler way?