(untested) ath fix upon error

[Andriy Voskoboinyk]

Tue, 03 Nov 2015 17:31:18 +0200 було написано Adrian Chadd  
<adrian at freebsd.org>:

> hiya,
>
> what do people think about this to fix ath(4) transmit errors:
>
> adrian at victoria:~/work/freebsd/head-embedded/src % svn diff sys/dev/ath
> Index: sys/dev/ath/if_ath.c
> ===================================================================
> --- sys/dev/ath/if_ath.c        (revision 290048)
> +++ sys/dev/ath/if_ath.c        (working copy)
> @@ -3320,6 +3320,9 @@
>          *
>          * Note: if this fails, then the mbufs are freed but
>          * not the node reference.
> +        *
> +        * So, we now have to free the node reference ourselves here
> +        * and return OK up to the stack.
>          */
>         next = m->m_nextpkt;
>         if (ath_tx_start(sc, ni, bf, m)) {
> @@ -3336,7 +3339,14 @@
>                  */
>                 ath_txfrag_cleanup(sc, &frags, ni);
>                 ATH_TXBUF_UNLOCK(sc);
> -               retval = ENOBUFS;
> +
> +               /*
> +                * XXX: And free the node/return OK; ath_tx_start() may  
> have
> +                *      modified the buffer.  We currently have no way to
> +                *      signify that the mbuf was freed but there was an  
> error.
> +                */
> +               ieee80211_node_free(ni);
> +               retval = 0;
>                 goto finish;
>         }
>
>
> .. the idea is that we can't return failure once we've called
> ath_tx_start(), as the mbuf needs to be consumed. So we return OK and
> just count an error.
>

Yes, I think this (temporary?) workaround should fix the issue.

>
>
> -adrian