imx8mm/imx8mn hang on usb stop / ehci_shutdown

[Tim Harvey]

On Thu, Apr 27, 2023 at 11:52 AM Fabio Estevam <festevam at gmail.com> wrote:
>
> Hi Tim,
>
> On Thu, Apr 27, 2023 at 3:46 PM Tim Harvey <tharvey at gateworks.com> wrote:
>
> > Fabio,
> >
> > Do you have another board to test with that uses both imx8mm usb host
> > controllers? With your imx8mm dtsi sync added a simple 'usb start'
> > hangs on my imx8mm-gw71xx board when the second controller is enabled:
> > starting USB...
> > Bus usb at 32e40000: USB EHCI 1.00
> > Bus usb at 32e50000:
>
> No other imx8mm-based board here at the moment, sorry.
>
> Without the imx8mm.dtsi sync patch, I was able to reproduce the hang
> after running "usb start && usb stop".
>
> After the imx8mm.dtsi sync patch, I do not see the hang.
>

it's possible the dts sync is indeed needed to resolve the issue I'm
seeing but something else is needed along with it for usbotg2.

> > I don't believe the imx8mm-evk even has proper USB support in general
> > (which is probably why CMD_USB is not enabled). Only one port is
> > enabled in the dt and If I connect a USB-C to host cable with device
> > in it to that port a 'usb tree' does not even show the device
> > enumerated.
>
> Yes, in U-Boot there is no ptn5110 driver, so the imx8mm-evk is not complete.

just enable usbotg2 controller in dt for imx8mm-evk and you'll see the hang:

+&usbotg2 {
+       status = "okay";
+};
+

u-boot=> usb start
starting USB...
Bus usb at 32e40000: Bus usb at 32e50000:

Tim