Index: sys/dev/alc/if_alcreg.h
===================================================================
--- sys/dev/alc/if_alcreg.h	(revision 217553)
+++ sys/dev/alc/if_alcreg.h	(working copy)
@@ -724,6 +724,14 @@
 
 #define	ALC_TX_MIB_BASE			0x1760
 
+#define	ALC_CLK_GATING_CFG		0x1814
+#define	CLK_GATING_DMAW_ENB		0x0001
+#define	CLK_GATING_DMAR_ENB		0x0002
+#define	CLK_GATING_TXQ_ENB		0x0004
+#define	CLK_GATING_RXQ_ENB		0x0008
+#define	CLK_GATING_TXMAC_ENB		0x0010
+#define	CLK_GATING_RXMAC_ENB		0x0020
+
 #define	ALC_DEBUG_DATA0			0x1900
 
 #define	ALC_DEBUG_DATA1			0x1904
Index: sys/dev/alc/if_alc.c
===================================================================
--- sys/dev/alc/if_alc.c	(revision 217553)
+++ sys/dev/alc/if_alc.c	(working copy)
@@ -3148,6 +3148,9 @@
 	alc_init_cmb(sc);
 	alc_init_smb(sc);
 
+	/* Enable all clocks. */
+	CSR_WRITE_4(sc, ALC_CLK_GATING_CFG, 0);
+
 	/* Reprogram the station address. */
 	bcopy(IF_LLADDR(ifp), eaddr, ETHER_ADDR_LEN);
 	CSR_WRITE_4(sc, ALC_PAR0,