EM120 not correctly booting up, unknown wwan control port exposed?

[Loic Poulain]

On Sun, 23 May 2021 at 21:58, Aleksander Morgado
<aleksander at aleksander.es> wrote:
>
> Hey,
>
> > >
> > > I wanted to test the EM120 setup I have with latest MM git master and
> > > kernel 5.13.0-rc2, but unfortunately there is some issue, not sure if
> > > in device or in kernel driver. These are the kernel logs I get as
> > > output when the issue happens:
> > >
> > > [  263.458712] mhi-pci-generic 0000:01:00.0: can't change power state
> > > from D3cold to D0 (config space inaccessible)
> > > [  263.458727] mhi-pci-generic 0000:01:00.0: can't change power state
> > > from D3cold to D0 (config space inaccessible)
> > > [  263.458736] mhi-pci-generic 0000:01:00.0: failed to resume device: -22
> >
> > The problem seems to be with the runtime power management. MHI pci
> > driver is moving the device in low power state (suspend) when not used
> > for ~2s. And here device resume fails. How the EM120 is connected to
> > your machine is it via M2 laptop port or are you using a 'dev-board'
> > with PCI-express slot? can you share the firmware version? building
> > mainline right now and going to test that on my side.

It works correctly on my side.

> >
>
> This is with a EM120 devkit in a PCI-express slot in my desktop PC,
> running firmware EM120RGLAPR02A07.

Ok mine is EM120RGLAPR02A07M4G (from --query-device-caps output).

Maybe the suspend issue is due to the devkit. But better to confirm with Carl.

> I tested this setup some months ago with the "mhi_uci_q" driver from
> Quectel, and I didn't see any problem like this.

Runtime PM was probably not enabled/implemented. For now, maybe apply
`ATTR{power/control}="on"` for this device, which should prevent
dynamic runtime PM.

Regards,
Loic

>
>
> --
> Aleksander
> https://aleksander.es