i.MX8MM USB autosuspend broken with power domain support

[Frieder Schrempf]

Hi,

when power domain support was added for i.MX8MM, it seems like this
broke the USB autosuspend feature.

I reported this previously when testing the gpcv2 patches before they
were merged [1] and the issue can also be reproduced on v5.18-rc2.

Did anyone else encounter such a problem? Can anyone help with debugging
or proposing a fix?

Do the USB power domains need to stay enabled for autosuspend to work?
If yes how can this be achieved?

Below is some more information on how to reproduce the issue including
some debug output.

Thanks a lot and best regards
Frieder

1. Plug in USB device on host port, device is not enumerated, no debug
output

2. Disable autosuspend, device gets enumerated

~# echo on > /sys/bus/usb/devices/usb1/power/control
[ 2986.582786] imx_usb 32e40000.usb: genpd_runtime_resume()
[ 2986.588155] imx-pgc imx-pgc-domain.2: genpd_runtime_resume()
[ 2986.593876] imx-pgc imx-pgc-domain.2: resume latency exceeded, 1125 ns
[ 2986.600446] PM: usb-otg1: Power-on latency exceeded, new value
12295000 ns
[ 2986.607342] imx_usb 32e40000.usb: at imx_controller_resume
[ 2986.612850] ci_hdrc ci_hdrc.0: genpd_runtime_resume()
[ 2986.617919] ci_hdrc ci_hdrc.0: at ci_controller_resume
[ 2986.858565] usb 1-1: new full-speed USB device number 10 using ci_hdrc

[1] https://lkml.org/lkml/2021/5/19/883