On Thu, Feb 20, 2020 at 05:50:03PM +1100, Evan Benn wrote:
> > > + if ((int)res->a0 == PSCI_RET_NOT_SUPPORTED)
> > > + return -ENOTSUPP;
> >
> > -ENODEV would be better here.
> >
> > > + if ((int)res->a0 == PSCI_RET_INVALID_PARAMS)
> > > + return -EINVAL;
> > > + if ((int)res->a0 < 0)
> > > + return -EIO;
>
> In fixing this I found drivers/firmware/psci/psci.c:145
> Which also translates psci codes to errno codes, but uses EOPNOTSUPP:
>
> switch (errno) {
> case PSCI_RET_SUCCESS:
> return 0;
> case PSCI_RET_NOT_SUPPORTED:
> return -EOPNOTSUPP;
> case PSCI_RET_INVALID_PARAMS:
> case PSCI_RET_INVALID_ADDRESS:
> return -EINVAL;
> case PSCI_RET_DENIED:
> return -EPERM;
> };
>
> return -EINVAL;
>
> Are these more appropriate?
>
It is customary for driver probe functions to return -ENODEV if the
device is not supported. I don't see a reason why this driver should
behave any different. "but this other driver does it" is never a good
argument.
Having said that, yet, with the exception of -EOPNOTSUPP the other
return values would be more appropriate.
Guenter
