C2 kernel usb fix

[tech-todd]

I only test on my OdroidC2 so this find may affect more.

As repeatedly mentioned, the C2 has usb detect issues.

For us, a main culprit not discussed yet is the default kernel config.

Having both:

CONFIG_USB_EHCI_TT_NEWSCHED=Y

CONFIG_USB_OHCI_HCD=Y

 

For USB1.1, these should be one or the other, never both.

Mainline has: CONFIG_USB_OHCI_HCD=Y and CONFIG_USB_EHCI_TT_NEWSCHED is not set.

For the OdroidC2, CONFIG_USB_OHCI_HCD=N is proper.
As it has no OHCI and USB2 handles that for us.

 

Forcing the USB power on state has helped workaround this issue, by keeping the driver tied to the device in the kernel.

[tech-todd]

During build compile, set kernel config as:

Device Drivers -> USB Support -> xHCI HCD (USB 3.0) support N
Device Drivers -> USB Support -> OHCI HCD (USB 1.1) support N
Device Drivers -> USB Support -> DesignWare USB3 DRD Core N

 

should alleviate most usb issues on a OdroidC2