Reorder interrupt handler a bit such that producer/consumer

index of status block is read first before acknowledging the
interrupts. Otherwise bge(4) may get stale status block as
acknowledging an interrupt may yield another status block update.

Reviewed by:	marius

1 files changed, 16 insertions, 16 deletions

diff --git a/sys/dev/bge/if_bge.c b/sys/dev/bge/if_bge.c
index b21fd72..679d202 100644
--- a/sys/dev/bge/if_bge.c
+++ b/sys/dev/bge/if_bge.c
@@ -3654,6 +3654,22 @@ bge_intr(void *xsc)
 #endif
 
 	/*
+	 * Do the mandatory PCI flush as well as get the link status.
+	 */
+	statusword = CSR_READ_4(sc, BGE_MAC_STS) & BGE_MACSTAT_LINK_CHANGED;
+
+	/* Make sure the descriptor ring indexes are coherent. */
+	bus_dmamap_sync(sc->bge_cdata.bge_status_tag,
+	    sc->bge_cdata.bge_status_map,
+	    BUS_DMASYNC_POSTREAD | BUS_DMASYNC_POSTWRITE);
+	rx_prod = sc->bge_ldata.bge_status_block->bge_idx[0].bge_rx_prod_idx;
+	tx_cons = sc->bge_ldata.bge_status_block->bge_idx[0].bge_tx_cons_idx;
+	sc->bge_ldata.bge_status_block->bge_status = 0;
+	bus_dmamap_sync(sc->bge_cdata.bge_status_tag,
+	    sc->bge_cdata.bge_status_map,
+	    BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
+
+	/*
 	 * Ack the interrupt by writing something to BGE_MBX_IRQ0_LO.  Don't
 	 * disable interrupts by writing nonzero like we used to, since with
 	 * our current organization this just gives complications and
@@ -3675,22 +3691,6 @@ bge_intr(void *xsc)
 	 */
 	bge_writembx(sc, BGE_MBX_IRQ0_LO, 0);
 
-	/*
-	 * Do the mandatory PCI flush as well as get the link status.
-	 */
-	statusword = CSR_READ_4(sc, BGE_MAC_STS) & BGE_MACSTAT_LINK_CHANGED;
-
-	/* Make sure the descriptor ring indexes are coherent. */
-	bus_dmamap_sync(sc->bge_cdata.bge_status_tag,
-	    sc->bge_cdata.bge_status_map,
-	    BUS_DMASYNC_POSTREAD | BUS_DMASYNC_POSTWRITE);
-	rx_prod = sc->bge_ldata.bge_status_block->bge_idx[0].bge_rx_prod_idx;
-	tx_cons = sc->bge_ldata.bge_status_block->bge_idx[0].bge_tx_cons_idx;
-	sc->bge_ldata.bge_status_block->bge_status = 0;
-	bus_dmamap_sync(sc->bge_cdata.bge_status_tag,
-	    sc->bge_cdata.bge_status_map,
-	    BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
-
 	if ((sc->bge_asicrev == BGE_ASICREV_BCM5700 &&
 	    sc->bge_chipid != BGE_CHIPID_BCM5700_B2) ||
 	    statusword || sc->bge_link_evt)