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Be more robust when handling Rx interrupts. If we can't allocate and DMA map

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a new mbuf, just discard the received frame and reuse the old mbuf.
This should fix kernel panics on high network traffic.

MFC after:	2 weeks
This commit is contained in:
Damien Bergamini 2005-11-13 17:19:12 +00:00
parent 4c4102ec52
commit ca5b70c4fa
1 changed files with 41 additions and 21 deletions
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62
sys/dev/ral/if_ral.c
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@ -1317,7 +1317,7 @@ ral_decryption_intr(struct ral_softc *sc)
struct ieee80211_frame *wh;
struct ieee80211_node *ni;
struct ral_node *rn;
struct mbuf *m;
struct mbuf *mnew, *m;
int hw, error;
/* retrieve last decriptor index processed by cipher engine */
@ -1345,12 +1345,51 @@ ral_decryption_intr(struct ral_softc *sc)
goto skip;
}
/*
* Try to allocate a new mbuf for this ring element and load it
* before processing the current mbuf. If the ring element
* cannot be loaded, drop the received packet and reuse the old
* mbuf. In the unlikely case that the old mbuf can't be
* reloaded either, explicitly panic.
*/
mnew = m_getcl(M_DONTWAIT, MT_DATA, M_PKTHDR);
if (mnew == NULL) {
ifp->if_ierrors++;
goto skip;
}
bus_dmamap_sync(sc->rxq.data_dmat, data->map,
BUS_DMASYNC_POSTREAD);
bus_dmamap_unload(sc->rxq.data_dmat, data->map);
/* finalize mbuf */
error = bus_dmamap_load(sc->rxq.data_dmat, data->map,
mtod(mnew, void *), MCLBYTES, ral_dma_map_addr, &physaddr,
0);
if (error != 0) {
m_freem(mnew);
/* try to reload the old mbuf */
error = bus_dmamap_load(sc->rxq.data_dmat, data->map,
mtod(data->m, void *), MCLBYTES, ral_dma_map_addr,
&physaddr, 0);
if (error != 0) {
/* very unlikely that it will fail... */
panic("%s: could not load old rx mbuf",
device_get_name(sc->sc_dev));
}
ifp->if_ierrors++;
goto skip;
}
/*
* New mbuf successfully loaded, update Rx ring and continue
* processing.
*/
m = data->m;
data->m = mnew;
desc->physaddr = htole32(physaddr);
/* finalize mbuf */
m->m_pkthdr.rcvif = ifp;
m->m_pkthdr.len = m->m_len =
(le32toh(desc->flags) >> 16) & 0xfff;
@ -1389,25 +1428,6 @@ ral_decryption_intr(struct ral_softc *sc)
/* node is no longer needed */
ieee80211_free_node(ni);
data->m = m_getcl(M_DONTWAIT, MT_DATA, M_PKTHDR);
if (data->m == NULL) {
device_printf(sc->sc_dev,
"could not allocate rx mbuf\n");
break;
}
error = bus_dmamap_load(sc->rxq.data_dmat, data->map,
mtod(data->m, void *), MCLBYTES, ral_dma_map_addr,
&physaddr, 0);
if (error != 0) {
device_printf(sc->sc_dev,
"could not load rx buf DMA map\n");
m_freem(data->m);
data->m = NULL;
break;
}
desc->physaddr = htole32(physaddr);
skip: desc->flags = htole32(RAL_RX_BUSY);
DPRINTFN(15, ("decryption done idx=%u\n", sc->rxq.cur_decrypt));