i.MX8MM USB autosuspend broken with power domain support

[Fabio Estevam]

[Adding Jun Li]

On Wed, Apr 13, 2022 at 11:35 AM Frieder Schrempf
<frieder.schrempf at kontron.de> wrote:
>
> 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