Re: [Qemu-devel] [RFC PATCH v0 2/3] spapr-rtas: Enable rtas_set_indicator() to return correct error

[Michael Roth <mdroth@linux.vnet.ibm.com>]

Quoting Bharata B Rao (2015-08-19 01:56:10)
> drck->set_isolation_state() can return error. For such a case ensure
> correct error is returned by rtas_set_indicator() instead of always
> returning success.
> 
> TODO: rtas_st(, , uint32 val) => the return value uint32, but
> drck->set_[allocation/indicator/isolation]_state() is returning int.
> Should we change this return value to uint32_t to match with rtas_st()
> argument ?

I wouldn't bother too much aligning the types unless we go to the extent
of documenting these interfaces as returning rtas error codes. That's
not really the case currently, and there's a lot of rtas errors that
don't really need to be determined by DRC code so I think it's more
trouble than it's worth.

For now I think it's better to just check for ret != 0 and set return
values explicitly in rtas code based on what the drc errors entail.

> 
> Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com>
> ---
>  hw/ppc/spapr_rtas.c | 9 +++++----
>  1 file changed, 5 insertions(+), 4 deletions(-)
> 
> diff --git a/hw/ppc/spapr_rtas.c b/hw/ppc/spapr_rtas.c
> index e99e25f..96729b4 100644
> --- a/hw/ppc/spapr_rtas.c
> +++ b/hw/ppc/spapr_rtas.c
> @@ -374,6 +374,7 @@ static void rtas_set_indicator(PowerPCCPU *cpu, sPAPRMachineState *spapr,
>      uint32_t sensor_state;
>      sPAPRDRConnector *drc;
>      sPAPRDRConnectorClass *drck;
> +    int ret;
> 
>      if (nargs != 3 || nret != 1) {
>          rtas_st(rets, 0, RTAS_OUT_PARAM_ERROR);
> @@ -413,19 +414,19 @@ static void rtas_set_indicator(PowerPCCPU *cpu, sPAPRMachineState *spapr,
>                  spapr_ccs_remove(spapr, ccs);
>              }
>          }
> -        drck->set_isolation_state(drc, sensor_state);
> +        ret = drck->set_isolation_state(drc, sensor_state);
>          break;
>      case RTAS_SENSOR_TYPE_DR:
> -        drck->set_indicator_state(drc, sensor_state);
> +        ret = drck->set_indicator_state(drc, sensor_state);
>          break;
>      case RTAS_SENSOR_TYPE_ALLOCATION_STATE:
> -        drck->set_allocation_state(drc, sensor_state);
> +        ret = drck->set_allocation_state(drc, sensor_state);
>          break;
>      default:
>          goto out_unimplemented;
>      }
> 
> -    rtas_st(rets, 0, RTAS_OUT_SUCCESS);
> +    rtas_st(rets, 0, ret);
>      return;
> 
>  out_unimplemented:
> -- 
> 2.1.0
>