Index: sys/dev/msk/if_msk.c
===================================================================
--- sys/dev/msk/if_msk.c	(revision 186497)
+++ sys/dev/msk/if_msk.c	(working copy)
@@ -1355,27 +1355,25 @@
 	CSR_WRITE_4(sc, STAT_LIST_ADDR_HI, MSK_ADDR_HI(addr));
 	/* Set the status list last index. */
 	CSR_WRITE_2(sc, STAT_LAST_IDX, MSK_STAT_RING_CNT - 1);
-	if (sc->msk_hw_id == CHIP_ID_YUKON_EC &&
-	    sc->msk_hw_rev == CHIP_REV_YU_EC_A1) {
-		/* WA for dev. #4.3 */
-		CSR_WRITE_2(sc, STAT_TX_IDX_TH, ST_TXTH_IDX_MASK);
-		/* WA for dev. #4.18 */
-		CSR_WRITE_1(sc, STAT_FIFO_WM, 0x21);
-		CSR_WRITE_1(sc, STAT_FIFO_ISR_WM, 0x07);
-	} else {
-		CSR_WRITE_2(sc, STAT_TX_IDX_TH, 0x0a);
-		CSR_WRITE_1(sc, STAT_FIFO_WM, 0x10);
-		if (sc->msk_hw_id == CHIP_ID_YUKON_XL &&
-		    sc->msk_hw_rev == CHIP_REV_YU_XL_A0)
-			CSR_WRITE_1(sc, STAT_FIFO_ISR_WM, 0x04);
-		else
-			CSR_WRITE_1(sc, STAT_FIFO_ISR_WM, 0x10);
-		CSR_WRITE_4(sc, STAT_ISR_TIMER_INI, 0x0190);
-	}
 	/*
-	 * Use default value for STAT_ISR_TIMER_INI, STAT_LEV_TIMER_INI.
+	 * Interrupt moderation and coalescing frames should be
+	 * controllable with sysctl variables or loader tunables
+	 * but the relationship between status updates and
+	 * interrupt moderation are not clear. Some hardware
+	 * revisions seem to very sensitive to these parameters
+	 * and could be resulted in poor performance as well as 
+	 * non-working situation if improper values were chosen.
 	 */
+	CSR_WRITE_2(sc, STAT_TX_IDX_TH, 0x0a);
+	CSR_WRITE_1(sc, STAT_FIFO_WM, 0x10);
+	if (sc->msk_hw_id == CHIP_ID_YUKON_XL &&
+	    sc->msk_hw_rev == CHIP_REV_YU_XL_A0)
+		CSR_WRITE_1(sc, STAT_FIFO_ISR_WM, 0x04);
+	else
+		CSR_WRITE_1(sc, STAT_FIFO_ISR_WM, 0x10);
 	CSR_WRITE_4(sc, STAT_TX_TIMER_INI, MSK_USECS(sc, 1000));
+	CSR_WRITE_4(sc, STAT_ISR_TIMER_INI, MSK_USECS(sc, 30));
+	CSR_WRITE_4(sc, STAT_LEV_TIMER_INI, MSK_USECS(sc, 50));
 
 	/* Enable status unit. */
 	CSR_WRITE_4(sc, STAT_CTRL, SC_STAT_OP_ON);
@@ -3586,6 +3584,10 @@
 	domore = msk_handle_events(sc);
 	if ((status & Y2_IS_STAT_BMU) != 0)
 		CSR_WRITE_4(sc, STAT_CTRL, SC_STAT_CLR_IRQ);
+	if (CSR_READ_1(sc, STAT_TX_TIMER_CTRL) == TIM_START) {
+		CSR_WRITE_1(sc, STAT_TX_TIMER_CTRL, TIM_STOP);
+		CSR_WRITE_1(sc, STAT_TX_TIMER_CTRL, TIM_START);
+	}
 
 	if (ifp0 != NULL && (ifp0->if_drv_flags & IFF_DRV_RUNNING) != 0 &&
 	    !IFQ_DRV_IS_EMPTY(&ifp0->if_snd))