d/freebsd-skq
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Add busdma sync ops before reading and after modifying the descriptor rings.

Browse Source 
This was previously working by accident because BUSDMA_COHERENT_MEMORY has
always been set to strongly-ordered on arm.  Now we're moving towards
normal-uncacheable (what might be called write-combining on other platforms)
and using the proper sync ops will be more important.  Of course, that
opens the question of just what is the "proper" sync op for shared
concurrent dma access as opposed to accesses where the handoff of control
of the memory has well-defined sequence points that match the available
busdma sync operations.
This commit is contained in:
ian 2014-11-24 16:12:11 +00:00
parent 1f1e4bf8b6
commit edba26a69c
1 changed files with 10 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

10
sys/dev/ffec/if_ffec.c
View File

@ -652,7 +652,9 @@ ffec_txstart_locked(struct ffec_softc *sc)
}
if (enqueued != 0) {
bus_dmamap_sync(sc->txdesc_tag, sc->txdesc_map, BUS_DMASYNC_PREWRITE);
WR4(sc, FEC_TDAR_REG, FEC_TDAR_TDAR);
bus_dmamap_sync(sc->txdesc_tag, sc->txdesc_map, BUS_DMASYNC_POSTWRITE);
sc->tx_watchdog_count = WATCHDOG_TIMEOUT_SECS;
}
}
@ -677,6 +679,9 @@ ffec_txfinish_locked(struct ffec_softc *sc)
FFEC_ASSERT_LOCKED(sc);
/* XXX Can't set PRE|POST right now, but we need both. */
bus_dmamap_sync(sc->txdesc_tag, sc->txdesc_map, BUS_DMASYNC_PREREAD);
bus_dmamap_sync(sc->txdesc_tag, sc->txdesc_map, BUS_DMASYNC_POSTREAD);
ifp = sc->ifp;
retired_buffer = false;
while (sc->tx_idx_tail != sc->tx_idx_head) {
@ -841,6 +846,9 @@ ffec_rxfinish_locked(struct ffec_softc *sc)
FFEC_ASSERT_LOCKED(sc);
/* XXX Can't set PRE|POST right now, but we need both. */
bus_dmamap_sync(sc->rxdesc_tag, sc->rxdesc_map, BUS_DMASYNC_PREREAD);
bus_dmamap_sync(sc->rxdesc_tag, sc->rxdesc_map, BUS_DMASYNC_POSTREAD);
produced_empty_buffer = false;
for (;;) {
desc = &sc->rxdesc_ring[sc->rx_idx];
@ -888,7 +896,9 @@ ffec_rxfinish_locked(struct ffec_softc *sc)
}
if (produced_empty_buffer) {
bus_dmamap_sync(sc->rxdesc_tag, sc->txdesc_map, BUS_DMASYNC_PREWRITE);
WR4(sc, FEC_RDAR_REG, FEC_RDAR_RDAR);
bus_dmamap_sync(sc->rxdesc_tag, sc->txdesc_map, BUS_DMASYNC_POSTWRITE);
}
}