We have MCU K61 is used with uClinux.
USB hub is connected to K61 USBOTG (USBFS) controller in host mode. The hub is successfully enumerated by Linux with khci hcd driver. But when the hub's interrupt pipe polled for status hub returns NAK all the time. No USB devices connected to the hub can be detected.
On other hand a single USB device connected to K61 USBOTG controller port works just file.
Please advise how to make USB hub work with K61 USBOTG controller under uClinux.