o TxD ring requires 8 bytes alignment to work so change alignment

   constraint to 8. Previously it may have triggered watchdog
   timeouts.
 o Check whether interrupt is ours or not.
 o Enable interrupts before attemping to transmit queued packets.
   This will slightly improve TX performance.
 o No need to clear IFF_DRV_OACTIVE in a loop. AE_FLAG_TXAVAIL is
   used to know whether there are enough available TxD ring space.
 o Added missing bus_dmamap_sync(9) in ae_rx_intr() and rearranged
   code to avoid unncessary register access.
 o Make sure to clear TxD, TxS, RxD rings in driver initialization.
   Otherwise some data in these rings could be interpreted as
   'updated' which in turn will advance internally maintained
   pointers and can trigger watchdog timeouts.

PR:	kern/180382

1 files changed, 30 insertions, 20 deletions

diff --git a/sys/dev/ae/if_ae.c b/sys/dev/ae/if_ae.c
index e49b926..306a296 100644
--- a/sys/dev/ae/if_ae.c
+++ b/sys/dev/ae/if_ae.c
@@ -585,6 +585,9 @@ ae_init_locked(ae_softc_t *sc)
 	val = eaddr[0] << 8 | eaddr[1];
 	AE_WRITE_4(sc, AE_EADDR1_REG, val);
 
+	bzero(sc->rxd_base_dma, AE_RXD_COUNT_DEFAULT * 1536 + 120);
+	bzero(sc->txd_base, AE_TXD_BUFSIZE_DEFAULT);
+	bzero(sc->txs_base, AE_TXS_COUNT_DEFAULT * 4);
 	/*
 	 * Set ring buffers base addresses.
 	 */
@@ -1115,7 +1118,7 @@ ae_alloc_rings(ae_softc_t *sc)
 	 * Create DMA tag for TxD.
 	 */
 	error = bus_dma_tag_create(sc->dma_parent_tag,
-	    4, 0, BUS_SPACE_MAXADDR, BUS_SPACE_MAXADDR,
+	    8, 0, BUS_SPACE_MAXADDR, BUS_SPACE_MAXADDR,
 	    NULL, NULL, AE_TXD_BUFSIZE_DEFAULT, 1,
 	    AE_TXD_BUFSIZE_DEFAULT, 0, NULL, NULL,
 	    &sc->dma_txd_tag);
@@ -1128,7 +1131,7 @@ ae_alloc_rings(ae_softc_t *sc)
 	 * Create DMA tag for TxS.
 	 */
 	error = bus_dma_tag_create(sc->dma_parent_tag,
-	    4, 0, BUS_SPACE_MAXADDR, BUS_SPACE_MAXADDR,
+	    8, 0, BUS_SPACE_MAXADDR, BUS_SPACE_MAXADDR,
 	    NULL, NULL, AE_TXS_COUNT_DEFAULT * 4, 1,
 	    AE_TXS_COUNT_DEFAULT * 4, 0, NULL, NULL,
 	    &sc->dma_txs_tag);
@@ -1761,6 +1764,10 @@ ae_int_task(void *arg, int pending)
 	ifp = sc->ifp;
 
 	val = AE_READ_4(sc, AE_ISR_REG);	/* Read interrupt status. */
+	if (val == 0) {
+		AE_UNLOCK(sc);
+		return;
+	}
 
 	/*
 	 * Clear interrupts and disable them.
@@ -1783,12 +1790,16 @@ ae_int_task(void *arg, int pending)
 			ae_tx_intr(sc);
 		if ((val & AE_ISR_RX_EVENT) != 0)
 			ae_rx_intr(sc);
-	}
+		/*
+		 * Re-enable interrupts.
+		 */
+		AE_WRITE_4(sc, AE_ISR_REG, 0);
 
-	/*
-	 * Re-enable interrupts.
-	 */
-	AE_WRITE_4(sc, AE_ISR_REG, 0);
+		if ((sc->flags & AE_FLAG_TXAVAIL) != 0) {
+			if (!IFQ_DRV_IS_EMPTY(&ifp->if_snd))
+				ae_start_locked(ifp);
+		}
+	}
 
 	AE_UNLOCK(sc);
 }
@@ -1849,10 +1860,10 @@ ae_tx_intr(ae_softc_t *sc)
 			ifp->if_oerrors++;
 
 		sc->tx_inproc--;
-
-		ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
 	}
 
+	if ((sc->flags & AE_FLAG_TXAVAIL) != 0)
+		ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
 	if (sc->tx_inproc < 0) {
 		if_printf(ifp, "Received stray Tx interrupt(s).\n");
 		sc->tx_inproc = 0;
@@ -1860,11 +1871,6 @@ ae_tx_intr(ae_softc_t *sc)
 
 	if (sc->tx_inproc == 0)
 		sc->wd_timer = 0;	/* Unarm watchdog. */
-	
-	if ((sc->flags & AE_FLAG_TXAVAIL) != 0) {
-		if (!IFQ_DRV_IS_EMPTY(&ifp->if_snd))
-			ae_start_locked(ifp);
-	}
 
 	/*
 	 * Syncronize DMA buffers.
@@ -1923,7 +1929,7 @@ ae_rx_intr(ae_softc_t *sc)
 	ae_rxd_t *rxd;
 	struct ifnet *ifp;
 	uint16_t flags;
-	int error;
+	int count, error;
 
 	KASSERT(sc != NULL, ("[ae, %d]: sc is NULL!", __LINE__));
 
@@ -1937,7 +1943,7 @@ ae_rx_intr(ae_softc_t *sc)
 	bus_dmamap_sync(sc->dma_rxd_tag, sc->dma_rxd_map,
 	    BUS_DMASYNC_POSTREAD | BUS_DMASYNC_POSTWRITE);
 
-	for (;;) {
+	for (count = 0;; count++) {
 		rxd = (ae_rxd_t *)(sc->rxd_base + sc->rxd_cur);
 		flags = le16toh(rxd->flags);
 		if ((flags & AE_RXD_UPDATE) == 0)
@@ -1964,10 +1970,14 @@ ae_rx_intr(ae_softc_t *sc)
 		}
 	}
 
-	/*
-	 * Update Rx index.
-	 */
-	AE_WRITE_2(sc, AE_MB_RXD_IDX_REG, sc->rxd_cur);
+	if (count > 0) {
+		bus_dmamap_sync(sc->dma_rxd_tag, sc->dma_rxd_map,
+		    BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
+		/*
+		 * Update Rx index.
+		 */
+		AE_WRITE_2(sc, AE_MB_RXD_IDX_REG, sc->rxd_cur);
+	}
 }
 
 static void