[PATCH 3/3] libchip/network/if_fxp.c: do not use rtems_interrupt_disable.

[Gedare Bloom]

On Wed, Oct 12, 2016 at 4:26 AM,  <pisa at cmp.felk.cvut.cz> wrote:
> From: Pavel Pisa <pisa at cmp.felk.cvut.cz>
>
> The single write to memory or ioport output are mostly
> atomic operations already. The proper memory synchronization barrier
> should be used around them to guarantee ordering (sync or eieio
> on PowerPC for example) but because I have not found settable
> portable primitive only compiler barrier is used.
> It should be enough on x86 because the externally visible order
> should be/is guaranteed to be preserved on x86 architecture.
> ---
>  c/src/libchip/network/if_fxp.c | 11 ++++-------
>  1 file changed, 4 insertions(+), 7 deletions(-)
>
> diff --git a/c/src/libchip/network/if_fxp.c b/c/src/libchip/network/if_fxp.c
> index 4d9d983..c2ca419 100644
> --- a/c/src/libchip/network/if_fxp.c
> +++ b/c/src/libchip/network/if_fxp.c
> @@ -1130,7 +1130,6 @@ fxp_start(struct ifnet *ifp)
>  {
>         struct fxp_softc *sc = ifp->if_softc;
>         struct fxp_cb_tx *txp;
> -       rtems_interrupt_level level;
>
>         DBGLVL_PRINTK(3,"fxp_start called\n");
>
> @@ -1279,10 +1278,10 @@ tbdinit:
>         /*
>          * reenable interrupts
>          */
> -       rtems_interrupt_disable (level);
> +       RTEMS_COMPILER_MEMORY_BARRIER();
>         CSR_WRITE_1(sc, FXP_CSR_SCB_INTRCNTL,0);
>         bsp_interrupt_vector_enable(sc->irq_num);
Here you don't delete bsp_interrupt_vector_enable ...

> -       rtems_interrupt_enable (level);
> +       RTEMS_COMPILER_MEMORY_BARRIER();
>  }
>
>  /*
> @@ -1311,7 +1310,6 @@ static void fxp_daemon(void *xsc)
>         struct ifnet *ifp = &sc->sc_if;
>         u_int8_t statack;
>         rtems_event_set events;
> -       rtems_interrupt_level level;
>
>  #ifdef NOTUSED
>         if (sc->suspended) {
> @@ -1458,10 +1456,9 @@ rcvloop:
>           /*
>            * reenable interrupts
>            */
> -         rtems_interrupt_disable (level);
> +         RTEMS_COMPILER_MEMORY_BARRIER();
>           CSR_WRITE_1(sc, FXP_CSR_SCB_INTRCNTL,0);
> -         bsp_interrupt_vector_enable(sc->irq_num);
... here you do. Why are the cases different?

> -         rtems_interrupt_enable (level);
> +         RTEMS_COMPILER_MEMORY_BARRIER();
>         }
>  }
>
> --
> 1.9.1
>
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