On Wed, May 31, 2017 at 10:28 +1000, David Gwynne wrote:
> ie, do the space check before trying to dequeue and mbuf.
>
> this also moves it to using m_defrag.
>
Thanks, this looks good.
Forgot to mention that you can remove the
/* now we are committed to transmit the packet */
comment from both sk and msk as it doesn't reveal any sacred
truths anymore.
Same as with sk, I've got no real opinion regarding adding
BUS_DMA_STREAMING, but otherwise I'm OK.
> i dont have an msk plugged in and i dont know how to use the overdrive
> 1000 i have here. if someone could test and ok this, it would be
> great.
>
> Index: if_msk.c
> ===================================================================
> RCS file: /cvs/src/sys/dev/pci/if_msk.c,v
> retrieving revision 1.127
> diff -u -p -r1.127 if_msk.c
> --- if_msk.c 10 Apr 2017 02:15:54 -0000 1.127
> +++ if_msk.c 31 May 2017 00:27:04 -0000
> @@ -1489,31 +1489,20 @@ msk_encap(struct sk_if_softc *sc_if, str
>
> cur = frag = *txidx;
>
> -#ifdef MSK_DEBUG
> - if (mskdebug >= 2)
> - msk_dump_mbuf(m_head);
> -#endif
> -
> - /*
> - * Start packing the mbufs in this chain into
> - * the fragment pointers. Stop when we run out
> - * of fragments or hit the end of the mbuf chain.
> - */
> - if (bus_dmamap_load_mbuf(sc->sc_dmatag, txmap, m_head,
> - BUS_DMA_NOWAIT)) {
> - DPRINTFN(2, ("msk_encap: dmamap failed\n"));
> - return (ENOBUFS);
> - }
> -
> - entries = txmap->dm_nsegs * 2;
> - if (entries > (MSK_TX_RING_CNT - sc_if->sk_cdata.sk_tx_cnt - 2)) {
> - DPRINTFN(2, ("msk_encap: too few descriptors free\n"));
> - bus_dmamap_unload(sc->sc_dmatag, txmap);
> - return (ENOBUFS);
> + switch (bus_dmamap_load_mbuf(sc->sc_dmatag, txmap, m_head,
> + BUS_DMA_STREAMING | BUS_DMA_NOWAIT)) {
> + case 0:
> + break;
> + case EFBIG: /* mbuf chain is too fragmented */
> + if (m_defrag(m_head, M_DONTWAIT) == 0 &&
> + bus_dmamap_load_mbuf(sc->sc_dmatag, txmap, m_head,
> + BUS_DMA_STREAMING | BUS_DMA_NOWAIT) == 0)
> + break;
> + /* FALLTHROUGH */
> + default:
> + return (1);
> }
>
> - DPRINTFN(2, ("msk_encap: dm_nsegs=%d\n", txmap->dm_nsegs));
> -
> /* Sync the DMA map. */
> bus_dmamap_sync(sc->sc_dmatag, txmap, 0, txmap->dm_mapsize,
> BUS_DMASYNC_PREWRITE);
> @@ -1585,12 +1574,16 @@ msk_start(struct ifnet *ifp)
> struct sk_if_softc *sc_if = ifp->if_softc;
> struct mbuf *m_head = NULL;
> u_int32_t idx = sc_if->sk_cdata.sk_tx_prod;
> - int pkts = 0;
> + int post = 0;
>
> - DPRINTFN(2, ("msk_start\n"));
> + for (;;) {
> + if (sc_if->sk_cdata.sk_tx_cnt + (SK_NTXSEG * 2) + 1 >
> + MSK_TX_RING_CNT) {
> + ifq_set_oactive(&ifp->if_snd);
> + break;
> + }
>
> - while (sc_if->sk_cdata.sk_tx_chain[idx].sk_mbuf == NULL) {
> - m_head = ifq_deq_begin(&ifp->if_snd);
> + m_head = ifq_dequeue(&ifp->if_snd);
> if (m_head == NULL)
> break;
>
> @@ -1600,14 +1593,11 @@ msk_start(struct ifnet *ifp)
> * for the NIC to drain the ring.
> */
> if (msk_encap(sc_if, m_head, &idx)) {
> - ifq_deq_rollback(&ifp->if_snd, m_head);
> - ifq_set_oactive(&ifp->if_snd);
> - break;
> + m_freem(m_head);
> + continue;
> }
>
> /* now we are committed to transmit the packet */
> - ifq_deq_commit(&ifp->if_snd, m_head);
> - pkts++;
>
> /*
> * If there's a BPF listener, bounce a copy of this frame
> @@ -1617,18 +1607,17 @@ msk_start(struct ifnet *ifp)
> if (ifp->if_bpf)
> bpf_mtap(ifp->if_bpf, m_head, BPF_DIRECTION_OUT);
> #endif
> + post = 1;
> }
> - if (pkts == 0)
> + if (post == 0)
> return;
>
> /* Transmit */
> - if (idx != sc_if->sk_cdata.sk_tx_prod) {
> - sc_if->sk_cdata.sk_tx_prod = idx;
> - SK_IF_WRITE_2(sc_if, 1, SK_TXQA1_Y2_PREF_PUTIDX, idx);
> + sc_if->sk_cdata.sk_tx_prod = idx;
> + SK_IF_WRITE_2(sc_if, 1, SK_TXQA1_Y2_PREF_PUTIDX, idx);
>
> - /* Set a timeout in case the chip goes out to lunch. */
> - ifp->if_timer = MSK_TX_TIMEOUT;
> - }
> + /* Set a timeout in case the chip goes out to lunch. */
> + ifp->if_timer = MSK_TX_TIMEOUT;
> }
>
> void
>
