imx8mm/imx8mn hang on usb stop / ehci_shutdown

[Tim Harvey]

On Thu, Apr 27, 2023 at 11:58 AM Tim Harvey <tharvey at gateworks.com> wrote:
>
> 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

Fabio,

The patch series from Eugen Hristev which implements reference
counting for regulators [1] resolves my issue here so I consider this
thread closed.

Let's move the discussion regarding your dt sync to those threads.

Best Regards,

Tim
[1] https://patchwork.ozlabs.org/project/uboot/list/?series=351536