atm: [he] send idle cells instead of unassigned when in SDH mode

Signed-off-by: Chas Williams <chas@cmf.nrl.navy.mil>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/atm/he.c b/drivers/atm/he.c
index fc636a3..ea495b2 100644
--- a/drivers/atm/he.c
+++ b/drivers/atm/he.c
@@ -1555,6 +1555,7 @@
 		val = he_phy_get(he_dev->atm_dev, SUNI_TPOP_APM);
 		val = (val & ~SUNI_TPOP_APM_S) | (SUNI_TPOP_S_SDH << SUNI_TPOP_APM_S_SHIFT);
 		he_phy_put(he_dev->atm_dev, val, SUNI_TPOP_APM);
+		he_phy_put(he_dev->atm_dev, SUNI_TACP_IUCHP_CLP, SUNI_TACP_IUCHP);
 	}
 
 	/* 5.1.12 enable transmit and receive */