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Subject: Re: [PATCH] Fix OACTIVE for an(4)
From: Adrian Chadd <adrian@freebsd.org>
To: John Baldwin <jhb@freebsd.org>
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Hi,

On 1 October 2014 07:14, John Baldwin <jhb@freebsd.org> wrote:
> This small patch correctly sets OACTIVE when an(4) gets backed up.  Right now
> I believe it will never set the flag.  It is only an optimization, it should
> not affect correctness.
>
> Index: an/if_an.c
> ===================================================================
> --- an/if_an.c  (revision 270968)
> +++ an/if_an.c  (working copy)
> @@ -2906,11 +2906,11 @@
>                 CSR_WRITE_2(sc, AN_INT_EN(sc->mpi350), AN_INTRS(sc->mpi350));
>         }
>
> -       if (m0 != NULL)
> +       if (sc->an_rdata.an_tx_prod != idx) {
>                 ifp->if_drv_flags |= IFF_DRV_OACTIVE;
> +               sc->an_rdata.an_tx_prod = idx;
> +       }
>
> -       sc->an_rdata.an_tx_prod = idx;
> -
>         return;
>  }

I haven't looked at the rest of the driver; is everything else around
OACTIVE locked correctly and consistently?

There's no single-entry into if_start(). It can be called from
multiple paths at the same time.


-a