Re: [XEN PATCH 1/2] xen/console: drop return value from consoled_guest_rx/tx

[Stefano Stabellini <sstabellini@xxxxxxxxxx>]

On Fri, 23 Feb 2024, Nicola Vetrini wrote:
> These functions never saw a usage of their return value since
> they were introduced, so it can be dropped since their usages
> violate MISRA C Rule 17.7:
> "The value returned by a function having non-void return type shall be used".
> 
> No functional change.
> 
> Signed-off-by: Nicola Vetrini <nicola.vetrini@xxxxxxxxxxx>

Reviewed-by: Stefano Stabellini <sstabellini@xxxxxxxxxx>


> ---
>  xen/drivers/char/consoled.c | 17 +++++------------
>  xen/include/xen/consoled.h  |  4 ++--
>  2 files changed, 7 insertions(+), 14 deletions(-)
> 
> diff --git a/xen/drivers/char/consoled.c b/xen/drivers/char/consoled.c
> index 222e01844271..b415b632cecc 100644
> --- a/xen/drivers/char/consoled.c
> +++ b/xen/drivers/char/consoled.c
> @@ -43,13 +43,13 @@ struct xencons_interface *consoled_get_ring_addr(void)
>  static char buf[BUF_SZ + 1];
>  
>  /* Receives characters from a domain's PV console */
> -size_t consoled_guest_rx(void)
> +void consoled_guest_rx(void)
>  {
> -    size_t recv = 0, idx = 0;
> +    size_t idx = 0;
>      XENCONS_RING_IDX cons, prod;
>  
>      if ( !cons_ring )
> -        return 0;
> +        return;
>  
>      spin_lock(&rx_lock);
>  
> @@ -73,7 +73,6 @@ size_t consoled_guest_rx(void)
>          char c = cons_ring->out[MASK_XENCONS_IDX(cons++, cons_ring->out)];
>  
>          buf[idx++] = c;
> -        recv++;
>  
>          if ( idx >= BUF_SZ )
>          {
> @@ -92,18 +91,15 @@ size_t consoled_guest_rx(void)
>  
>   out:
>      spin_unlock(&rx_lock);
> -
> -    return recv;
>  }
>  
>  /* Sends a character into a domain's PV console */
> -size_t consoled_guest_tx(char c)
> +void consoled_guest_tx(char c)
>  {
> -    size_t sent = 0;
>      XENCONS_RING_IDX cons, prod;
>  
>      if ( !cons_ring )
> -        return 0;
> +        return;
>  
>      cons = ACCESS_ONCE(cons_ring->in_cons);
>      prod = cons_ring->in_prod;
> @@ -121,7 +117,6 @@ size_t consoled_guest_tx(char c)
>          goto notify;
>  
>      cons_ring->in[MASK_XENCONS_IDX(prod++, cons_ring->in)] = c;
> -    sent++;
>  
>      /* Write to the ring before updating the pointer */
>      smp_wmb();
> @@ -130,8 +125,6 @@ size_t consoled_guest_tx(char c)
>   notify:
>      /* Always notify the guest: prevents receive path from getting stuck. */
>      pv_shim_inject_evtchn(pv_console_evtchn());
> -
> -    return sent;
>  }
>  
>  /*
> diff --git a/xen/include/xen/consoled.h b/xen/include/xen/consoled.h
> index 2b30516b3a0a..bd7ab6329ee8 100644
> --- a/xen/include/xen/consoled.h
> +++ b/xen/include/xen/consoled.h
> @@ -5,8 +5,8 @@
>  
>  void consoled_set_ring_addr(struct xencons_interface *ring);
>  struct xencons_interface *consoled_get_ring_addr(void);
> -size_t consoled_guest_rx(void);
> -size_t consoled_guest_tx(char c);
> +void consoled_guest_rx(void);
> +void consoled_guest_tx(char c);
>  
>  #endif /* __XEN_CONSOLED_H__ */
>  /*
> -- 
> 2.34.1
>