Fix the hangs people have been seeing. For some reason, the

atomic operation change caused this, so backout it until I
can figure out what's wrong with it.

1 files changed, 7 insertions, 11 deletions

diff --git a/sys/dev/fxp/if_fxp.c b/sys/dev/fxp/if_fxp.c
index 06bc6a0..e7adfd1 100644
--- a/sys/dev/fxp/if_fxp.c
+++ b/sys/dev/fxp/if_fxp.c
@@ -57,7 +57,6 @@ __FBSDID("$FreeBSD$");
 #include <net/ethernet.h>
 #include <net/if_arp.h>
 
-#include <machine/atomic.h>
 #include <machine/clock.h>	/* for DELAY */
 
 #include <net/if_types.h>
@@ -1208,7 +1207,7 @@ static void
 fxp_start(struct ifnet *ifp)
 {
 	struct fxp_softc *sc = ifp->if_softc;
-	struct fxp_tx *txp, *last;
+	struct fxp_tx *txp;
 	struct mbuf *mb_head;
 	int error;
 
@@ -1378,21 +1377,18 @@ fxp_start(struct ifnet *ifp)
 		 * Advance the end of list forward.
 		 */
 
+#ifdef __alpha__
 		/*
 		 * On platforms which can't access memory in 16-bit
 		 * granularities, we must prevent the card from DMA'ing
 		 * up the status while we update the command field.
 		 * This could cause us to overwrite the completion status.
-		 *
-		 * This is a bit tricky, because we want to avoid using
-		 * atomic operations on 16bits values, since they may not
-		 * be available on any architecture or may be very
-		 * inefficient.
 		 */
-		last = sc->fxp_desc.tx_last;
-		atomic_clear_32((u_int32_t *)&last->tx_cb->cb_status,
-		    htobe32(bswap16(FXP_CB_COMMAND_S)));
-
+		atomic_clear_short(&sc->fxp_desc.tx_last->tx_cb->cb_command,
+		    FXP_CB_COMMAND_S);
+#else
+		sc->fxp_desc.tx_last->tx_cb->cb_command &= ~FXP_CB_COMMAND_S;
+#endif /*__alpha__*/
 		sc->fxp_desc.tx_last = txp;
 
 		/*