> -----Original Message-----
> From: Francesco Dolcini <francesco@xxxxxxxxxx>
> Sent: Monday, October 31, 2022 9:54 PM
> To: Jun Li (OSS) <jun.li@xxxxxxxxxxx>
> Cc: Francesco Dolcini <francesco@xxxxxxxxxx>; Peter Chen
> <peter.chen@xxxxxxxxxx>; linux-usb@xxxxxxxxxxxxxxx; Greg Kroah-Hartman
> <gregkh@xxxxxxxxxxxxxxxxxxx>; Shawn Guo <shawnguo@xxxxxxxxxx>; Sascha
> Hauer <s.hauer@xxxxxxxxxxxxxx>; Pengutronix Kernel Team
> <kernel@xxxxxxxxxxxxxx>; Fabio Estevam <festevam@xxxxxxxxx>; dl-linux-imx
> <linux-imx@xxxxxxx>; Felipe Balbi <balbi@xxxxxxxxxx>;
> philippe.schenker@xxxxxxxxxxx; Francesco Dolcini
> <francesco.dolcini@xxxxxxxxxxx>
> Subject: Re: USB runtime PM issues on i.MX6ULL
>
> Hello Li Jun,
>
> On Mon, Oct 31, 2022 at 01:40:39PM +0000, Jun Li (OSS) wrote:
> > > -----Original Message-----
> > > From: Francesco Dolcini <francesco@xxxxxxxxxx>
> > > Sent: Friday, October 28, 2022 8:32 PM
> > > To: Peter Chen <peter.chen@xxxxxxxxxx>; linux-usb@xxxxxxxxxxxxxxx;
> > > Jun Li <jun.li@xxxxxxx>
> > > Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>; Shawn Guo
> > > <shawnguo@xxxxxxxxxx>; Sascha Hauer <s.hauer@xxxxxxxxxxxxxx>;
> > > Pengutronix Kernel Team <kernel@xxxxxxxxxxxxxx>; Fabio Estevam
> > > <festevam@xxxxxxxxx>; dl-linux-imx <linux-imx@xxxxxxx>; Felipe Balbi
> > > <balbi@xxxxxxxxxx>; philippe.schenker@xxxxxxxxxxx; Francesco Dolcini
> > > <francesco.dolcini@xxxxxxxxxxx>
> > > Subject: USB runtime PM issues on i.MX6ULL
> > >
> > > Hello all,
> > >
> > > I am debugging some unexpected USB behavior on a i.MX6ULL SOC,
> > > chipidea controller ("fsl,imx6ul-usb") and a fsl mxs usbphy
> > > ("fsl,imx6ul-usbphy").
> > >
> > > The HW design has 2 USB interface, the first one is dual-role, while
> > > the second one is a host port with NO way to re-read the VBUS
> > > (USB_OTG2_VBUS is not really connected, there is just a capacitor to
> > > GND).
> >
> > How is your USB_OTG1_VBUS status? Can you try to make your
> > USB_OTG1_VBUS pad has a valid VBUS voltage, then run your Host only
> > port test with runtime PM enabled?
>
> USB_OTG1_VBUS is tied to GND the same way as USB_OTG2_VBUS, not really
> straightforward to do such a test.
iMX6ULL need at least one valid VBUS(either from OTG1 or OTG2) as input to
power the internal USB LDO if I understand correctly, so you need change
your HW to meet this: for Host only port, you have to connect USB_OTG2_VBUS
to a valid VBUS and make it always present for simple. You can do some
quick HW change to prove this.
Li Jun
>
> Francesco
