Re: [PATCH 17/20] spapr: Remove unused return value in claim path

[Greg Kurz <groug@kaod.org>]

On Wed, 25 Sep 2019 16:45:31 +1000
David Gibson <david@gibson.dropbear.id.au> wrote:

> spapr_irq_claim() and the hooks it is based on return an integer error code
> as well as taking an Error ** parameter.  But none of the callers check the
> integer, so we can remove it and just use the richer Error **.
> 
> Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
> ---

FYI, the very same topic of using the return value versus Error ** to
check errors was discussed recently in this thread:

https://lists.gnu.org/archive/html/qemu-devel/2019-09/msg04197.html

I tend to agree with Daniel (Cc'd) at first thought, but I don't have a strong
opinion about this yet. It is mostly to inform you that people are currently
discussing/working on it.

>  hw/ppc/spapr_irq.c         | 32 +++++++++++++-------------------
>  include/hw/ppc/spapr_irq.h |  4 ++--
>  2 files changed, 15 insertions(+), 21 deletions(-)
> 
> diff --git a/hw/ppc/spapr_irq.c b/hw/ppc/spapr_irq.c
> index 261d66ba17..2673a90604 100644
> --- a/hw/ppc/spapr_irq.c
> +++ b/hw/ppc/spapr_irq.c
> @@ -112,8 +112,8 @@ static void spapr_irq_init_xics(SpaprMachineState *spapr, Error **errp)
>      spapr->ics = ICS_SPAPR(obj);
>  }
>  
> -static int spapr_irq_claim_xics(SpaprMachineState *spapr, int irq, bool lsi,
> -                                Error **errp)
> +static void spapr_irq_claim_xics(SpaprMachineState *spapr, int irq, bool lsi,
> +                                 Error **errp)
>  {
>      ICSState *ics = spapr->ics;
>  
> @@ -122,11 +122,10 @@ static int spapr_irq_claim_xics(SpaprMachineState *spapr, int irq, bool lsi,
>  
>      if (!ics_irq_free(ics, irq - ics->offset)) {
>          error_setg(errp, "IRQ %d is not free", irq);
> -        return -1;
> +        return;
>      }
>  
>      ics_set_irq_type(ics, irq - ics->offset, lsi);
> -    return 0;
>  }
>  
>  static void spapr_irq_free_xics(SpaprMachineState *spapr, int irq)
> @@ -252,14 +251,12 @@ static void spapr_irq_init_xive(SpaprMachineState *spapr, Error **errp)
>      spapr_xive_hcall_init(spapr);
>  }
>  
> -static int spapr_irq_claim_xive(SpaprMachineState *spapr, int irq, bool lsi,
> -                                Error **errp)
> +static void spapr_irq_claim_xive(SpaprMachineState *spapr, int irq, bool lsi,
> +                                 Error **errp)
>  {
>      if (!spapr_xive_irq_claim(spapr->xive, irq, lsi)) {
>          error_setg(errp, "IRQ %d is invalid", irq);
> -        return -1;
>      }
> -    return 0;
>  }
>  
>  static void spapr_irq_free_xive(SpaprMachineState *spapr, int irq)
> @@ -406,25 +403,22 @@ static void spapr_irq_init_dual(SpaprMachineState *spapr, Error **errp)
>      }
>  }
>  
> -static int spapr_irq_claim_dual(SpaprMachineState *spapr, int irq, bool lsi,
> -                                Error **errp)
> +static void spapr_irq_claim_dual(SpaprMachineState *spapr, int irq, bool lsi,
> +                                 Error **errp)
>  {
>      Error *local_err = NULL;
> -    int ret;
>  
> -    ret = spapr_irq_xics.claim(spapr, irq, lsi, &local_err);
> +    spapr_irq_xics.claim(spapr, irq, lsi, &local_err);
>      if (local_err) {
>          error_propagate(errp, local_err);
> -        return ret;
> +        return;
>      }
>  
> -    ret = spapr_irq_xive.claim(spapr, irq, lsi, &local_err);
> +    spapr_irq_xive.claim(spapr, irq, lsi, &local_err);
>      if (local_err) {
>          error_propagate(errp, local_err);
> -        return ret;
> +        return;
>      }
> -
> -    return ret;
>  }
>  
>  static void spapr_irq_free_dual(SpaprMachineState *spapr, int irq)
> @@ -622,12 +616,12 @@ void spapr_irq_init(SpaprMachineState *spapr, Error **errp)
>                                        spapr->irq->nr_xirqs + SPAPR_XIRQ_BASE);
>  }
>  
> -int spapr_irq_claim(SpaprMachineState *spapr, int irq, bool lsi, Error **errp)
> +void spapr_irq_claim(SpaprMachineState *spapr, int irq, bool lsi, Error **errp)
>  {
>      assert(irq >= SPAPR_XIRQ_BASE);
>      assert(irq < (spapr->irq->nr_xirqs + SPAPR_XIRQ_BASE));
>  
> -    return spapr->irq->claim(spapr, irq, lsi, errp);
> +    spapr->irq->claim(spapr, irq, lsi, errp);
>  }
>  
>  void spapr_irq_free(SpaprMachineState *spapr, int irq, int num)
> diff --git a/include/hw/ppc/spapr_irq.h b/include/hw/ppc/spapr_irq.h
> index ed88b4599a..75279ca137 100644
> --- a/include/hw/ppc/spapr_irq.h
> +++ b/include/hw/ppc/spapr_irq.h
> @@ -42,7 +42,7 @@ typedef struct SpaprIrq {
>      uint8_t     ov5;
>  
>      void (*init)(SpaprMachineState *spapr, Error **errp);
> -    int (*claim)(SpaprMachineState *spapr, int irq, bool lsi, Error **errp);
> +    void (*claim)(SpaprMachineState *spapr, int irq, bool lsi, Error **errp);
>      void (*free)(SpaprMachineState *spapr, int irq);
>      void (*print_info)(SpaprMachineState *spapr, Monitor *mon);
>      void (*dt_populate)(SpaprMachineState *spapr, uint32_t nr_servers,
> @@ -61,7 +61,7 @@ extern SpaprIrq spapr_irq_xive;
>  extern SpaprIrq spapr_irq_dual;
>  
>  void spapr_irq_init(SpaprMachineState *spapr, Error **errp);
> -int spapr_irq_claim(SpaprMachineState *spapr, int irq, bool lsi, Error **errp);
> +void spapr_irq_claim(SpaprMachineState *spapr, int irq, bool lsi, Error **errp);
>  void spapr_irq_free(SpaprMachineState *spapr, int irq, int num);
>  qemu_irq spapr_qirq(SpaprMachineState *spapr, int irq);
>  int spapr_irq_post_load(SpaprMachineState *spapr, int version_id);