Re: i.MX kernel hangup caused by chipidea USB gadget driver

Shawn Guo
2025-06-11T03:00:42Z

On Tue, Jun 10, 2025 at 07:54:41PM +0800, Xu Yang wrote:
> > However, your change seems working fine on i.MX8MM EVK. It's probably
> > due to the fact that host disconnects gadget for some reason when EVK
> > suspends. This is a different behavior from the custom board above.
> > We do not really expect this disconnecting, do we?
>
> It's an expected behavior on i.MX8MM EVK. The host will see device disconnected
> after imx8mm do system suspend. It's because the usb phy power will be off after
> system suspend. If you enable wakeup capabiklity for usb phy, the usb phy power
> will keep on and you will not see disconnect event anymore.
>
> # echo enabled > /sys/devices/platform/usbphynop1/power/wakeup

Ah, indeed! Thanks for the information!

Shawn