Re: 5.11-rc device reordering breaks ThinkPad rmi4 suspend

[Hugh Dickins]

On Mon, 11 Jan 2021, Rafael J. Wysocki wrote:
> On Mon, Jan 11, 2021 at 5:44 AM Hugh Dickins <hughd@xxxxxxxxxx> wrote:
> >
> > Hi Rafael,
> >
> > Synaptics RMI4 SMBus touchpad on ThinkPad X1 Carbon (5th generation)
> > fails to suspend when running 5.11-rc kernels: bisected to
> > 5b6164d3465f ("driver core: Reorder devices on successful probe"),
> > and reverting that fixes it.  dmesg.xz attached, but go ahead and ask
> > me to switch on a debug option to extract further info if that may help.
> 
> Does the driver abort the suspend transition by returning an error or
> does something else happen?

Both.  Thierry has pointed to the lines showing failed suspend transition;
and I forgot to mention that the touchpad is unresponsive from then on
(I might not have noticed the failed suspend without that).  But I don't
suppose that unresponsiveness is worth worrying about: things went wrong
in suspend, so it's not surprising if the driver does not recover well.

Thank you both for getting on to this so quickly - but don't worry about
getting my touchpad working: I'm glad to see you discussing the wider
issues of ordering that this has brought up.

Hugh