RE: [PATCH] watchdog: da9062: add power management ops

[Adam Thomson <Adam.Thomson.Opensource@diasemi.com>]

Hi Marco,

> > Hmmm. Wouldn't that then be a board specific fix rather than this change?
> > Am concerned relying on software to reenable the watchdog on resume could
> allow
> > for a hang scenario potentially if that code never gets to execute. Other
> > systems shouldn't need this fix, assuming they don't have issues at the HW
> > level, so this this seems like it could be making those systems less robust. If
> > we are to do this at the driver level, maybe this should be an option through DT
> > to help faulty systems, but I'm thinking this shouldn't be default behaviour.
> 
> I don't think that we should rely on the OTP values. Those values are
> set by Dialog, the SoM manufacturers or by the customer itself and the
> time shows that this is error prone too. At least if the customer or the
> SoM manufacturer don't ask the Dialog Support..
> 
> You're right with the (re-)enabling but there are other drivers using
> such an approach.. IMHO it is safer to go this way rather than trust
> the OTP and the PCB layout. I would rather add a dt-compatible to tell
> the driver to do nothing during suspend/resume e.g.:
> 
>     - dlg,use-hw-pm
> 
> or something. Because the user needs to validate the PCB and the OTP
> values.

The thing is the DT FW is supposed to be fairly static so I would rather not
enforce this change on users if they adopt a kernel version with this update in.
I also still think it's safer if the HW does this for us. I would have hoped for
most designs this would be caught in early bring up where it can be rectified
with minimal impact, although I'm guessing that's not the case in your scenario.

> Regards,
>   Marco