- When setting up a packet for transmit, if we the tx ring is over half

  full, kick the binary blob to force it to complete any pending tx
  completions.
- In the watchdog routine, only reset the chip if the blob doesn't complete
  any pending tx completions rather than requiring it to complete all of
  the pending tx completions.

Submitted by:	Nathan Whitehorn <nathanw@uchicago.edu>
MFC after:	2 weeks

1 files changed, 17 insertions, 3 deletions

diff --git a/sys/dev/nve/if_nve.c b/sys/dev/nve/if_nve.c
index 73b9aea..2f26a98 100644
--- a/sys/dev/nve/if_nve.c
+++ b/sys/dev/nve/if_nve.c
@@ -872,6 +872,17 @@ nve_ifstart_locked(struct ifnet *ifp)
 		if (m0 == NULL)
 			return;
 
+		/*
+		 * On nForce4, the chip doesn't interrupt on transmit,
+		 * so try to flush transmitted packets from the queue
+		 * if it's getting large (see note in nve_watchdog).
+		 */
+		if (sc->pending_txs > TX_RING_SIZE/2) {
+			sc->hwapi->pfnDisableInterrupts(sc->hwapi->pADCX);
+			sc->hwapi->pfnHandleInterrupt(sc->hwapi->pADCX);
+			sc->hwapi->pfnEnableInterrupts(sc->hwapi->pADCX);
+		}
+
 		/* Map MBUF for DMA access */
 		error = bus_dmamap_load_mbuf(sc->mtag, buf->map, m0,
 		    nve_dmamap_tx_cb, desc, BUS_DMA_NOWAIT);
@@ -1275,6 +1286,7 @@ static void
 nve_watchdog(struct ifnet *ifp)
 {
 	struct nve_softc *sc = ifp->if_softc;
+	int pending_txs_start;
 
 	NVE_LOCK(sc);
 
@@ -1283,14 +1295,16 @@ nve_watchdog(struct ifnet *ifp)
 	 * Thus, sometimes the watchdog timer will go off when the
 	 * tx engine is fine, but the tx completions are just deferred.
 	 * Try kicking the driver blob to clear out any pending tx
-	 * completions.  If that clears up all the pending tx
+	 * completions.  If that clears up any of the pending tx
 	 * operations, then just return without printing the warning
-	 * message or resetting the adapter.
+	 * message or resetting the adapter, as we can then conclude
+	 * the chip hasn't actually crashed (it's still sending packets).
 	 */
+	pending_txs_start = sc->pending_txs;
 	sc->hwapi->pfnDisableInterrupts(sc->hwapi->pADCX);
 	sc->hwapi->pfnHandleInterrupt(sc->hwapi->pADCX);
 	sc->hwapi->pfnEnableInterrupts(sc->hwapi->pADCX);
-	if (sc->pending_txs == 0) {
+	if (sc->pending_txs < pending_txs_start) {
 		NVE_UNLOCK(sc);
 		return;
 	}