On Thu, Apr 28, 2022 at 05:31:38PM -0500, Nathan Lynch wrote:
> Bjorn Helgaas <helgaas@xxxxxxxxxx> writes:
> > On Tue, Apr 26, 2022 at 11:07:39PM +0530, Mahesh Salgaonkar wrote:
> >> +/*
> >> + * RTAS call get-sensor-state(DR_ENTITY_SENSE) return values as per PAPR:
> >> + * -1: Hardware Error
> >> + * -2: RTAS_BUSY
> >> + * -3: Invalid sensor. RTAS Parameter Error.
> >> + * -9000: Need DR entity to be powered up and unisolated before RTAS call
> >> + * -9001: Need DR entity to be powered up, but not unisolated, before RTAS call
> >> + * -9002: DR entity unusable
> >> + * 990x: Extended delay - where x is a number in the range of 0-5
> >> + */
> >> +#define RTAS_HARDWARE_ERROR (-1)
> >> +#define RTAS_INVALID_SENSOR (-3)
> >> +#define SLOT_UNISOLATED (-9000)
> >> +#define SLOT_NOT_UNISOLATED (-9001)
> >> +static int rtas_to_errno(int rtas_rc)
> >> +{
> >> + int rc;
> >> +
> >> + switch (rtas_rc) {
> >> + case RTAS_HARDWARE_ERROR:
> >> + rc = -EIO;
> >> + break;
> >> + case RTAS_INVALID_SENSOR:
> >> + rc = -EINVAL;
> >> + break;
> >> + case SLOT_UNISOLATED:
> >> + case SLOT_NOT_UNISOLATED:
> >> + rc = -EFAULT;
> >> + break;
> >> + case SLOT_NOT_USABLE:
> >> + rc = -ENODEV;
> >> + break;
> >> + case RTAS_BUSY:
> >> + case RTAS_EXTENDED_DELAY_MIN...RTAS_EXTENDED_DELAY_MAX:
> >> + rc = -EBUSY;
> >> + break;
> >> + default:
> >> + err("%s: unexpected RTAS error %d\n", __func__, rtas_rc);
> >> + rc = -ERANGE;
> >> + break;
> >> + }
> >> + return rc;
> >
> > This basically duplicates rtas_error_rc(). Why do we need two copies?
>
> It treats RTAS_BUSY, RTAS_EXTENDED_DELAY_MIN...RTAS_EXTENDED_DELAY_MAX
> differently, which is part of the point of this change.
I think it would reduce confusion overall to:
- add RTAS_HARDWARE_ERROR, RTAS_INVALID_SENSOR to rtas.h
- rename and move SLOT_UNISOLATED, etc to rtas.h; they look
analogous to function-specific things like RTAS_SUSPEND_ABORTED
- change rtas_error_rc() to use the RTAS_HARDWARE_ERROR, etc
constants
- use the constants (SLOT_NOT_USABLE) instead of "9902" in the
commit log and code comments
> Aside: rtas_error_rc() (from powerpc's rtas.c) is badly named. Its
> conversions make sense for only a handful of RTAS calls. RTAS error
> codes have function-specific interpretations.
Maybe there's a case for factoring out the generic error codes and
have rtas_to_errno() (which sounds like maybe it should be renamed as
well) handle the function-specific part and fall back to the generic
one otherwise:
int rtas_to_errno(int rtas_rc)
{
switch (rtas_rc) {
case SLOT_UNISOLATED:
case SLOT_NOT_UNISOLATED:
return -EINVAL;
case SLOT_NOT_USABLE:
return -ENODEV;
...
default:
return rtas_error_rc(rtas_rc);
}
}
