bge: Add commented out code to set "clear ticks upon TX"

As far as I have tested, this coalesce mode does not have visiable
effect on both TX performance and interrupt rate.

To ease further tuning, the current TX performance and interrupt
rate that I have gathered on BCM5750 B1:
1472B UDP datagram   perf: 957Mbps, intr rate: ~1200Hz
18B   UDP datagram   perf: 565Kpps, intr rate: ~4400Hz

diff --git a/sys/dev/netif/bge/if_bge.c b/sys/dev/netif/bge/if_bge.c
index 2073609..433be82 100644 (file)
--- a/sys/dev/netif/bge/if_bge.c
+++ b/sys/dev/netif/bge/if_bge.c
@@ -1756,10 +1756,13 @@ bge_blockinit(struct bge_softc *sc)
                val = BGE_STATBLKSZ_32BYTE;
        }
 #if 0
-       if (sc->bge_flags & BGE_FLAG_STATUS_TAG) {
-               val |= 0x00000200 | 0x00000400;
-               if_printf(&sc->arpcom.ac_if, "enable TMR\n");
-       }
+       /*
+        * Does not seem to have visible effect in both
+        * bulk data (1472B UDP datagram) and tiny data
+        * (18B UDP datagram) TX tests.
+        */
+       if (!BGE_IS_CRIPPLED(sc))
+               val |= BGE_HCCMODE_CLRTICK_TX;
 #endif
 
        /* Turn on host coalescing state machine */