iwlagn: enable shadow register

For 6000 series devices and up, enable automatic update MAC's register
for better power usage in PSP mode

Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/iwlwifi/iwl-rx.c b/drivers/net/wireless/iwlwifi/iwl-rx.c
index baca4cc..87a6fd8 100644
--- a/drivers/net/wireless/iwlwifi/iwl-rx.c
+++ b/drivers/net/wireless/iwlwifi/iwl-rx.c
@@ -134,28 +134,37 @@
 	if (q->need_update == 0)
 		goto exit_unlock;
 
-	/* If power-saving is in use, make sure device is awake */
-	if (test_bit(STATUS_POWER_PMI, &priv->status)) {
-		reg = iwl_read32(priv, CSR_UCODE_DRV_GP1);
-
-		if (reg & CSR_UCODE_DRV_GP1_BIT_MAC_SLEEP) {
-			IWL_DEBUG_INFO(priv, "Rx queue requesting wakeup, GP1 = 0x%x\n",
-				      reg);
-			iwl_set_bit(priv, CSR_GP_CNTRL,
-				    CSR_GP_CNTRL_REG_FLAG_MAC_ACCESS_REQ);
-			goto exit_unlock;
-		}
-
-		q->write_actual = (q->write & ~0x7);
-		iwl_write_direct32(priv, rx_wrt_ptr_reg, q->write_actual);
-
-	/* Else device is assumed to be awake */
-	} else {
+	if (priv->cfg->base_params->shadow_reg_enable) {
+		/* shadow register enabled */
 		/* Device expects a multiple of 8 */
 		q->write_actual = (q->write & ~0x7);
 		iwl_write32(priv, rx_wrt_ptr_reg, q->write_actual);
-	}
+	} else {
+		/* If power-saving is in use, make sure device is awake */
+		if (test_bit(STATUS_POWER_PMI, &priv->status)) {
+			reg = iwl_read32(priv, CSR_UCODE_DRV_GP1);
 
+			if (reg & CSR_UCODE_DRV_GP1_BIT_MAC_SLEEP) {
+				IWL_DEBUG_INFO(priv,
+					"Rx queue requesting wakeup,"
+					" GP1 = 0x%x\n", reg);
+				iwl_set_bit(priv, CSR_GP_CNTRL,
+					CSR_GP_CNTRL_REG_FLAG_MAC_ACCESS_REQ);
+				goto exit_unlock;
+			}
+
+			q->write_actual = (q->write & ~0x7);
+			iwl_write_direct32(priv, rx_wrt_ptr_reg,
+					q->write_actual);
+
+		/* Else device is assumed to be awake */
+		} else {
+			/* Device expects a multiple of 8 */
+			q->write_actual = (q->write & ~0x7);
+			iwl_write_direct32(priv, rx_wrt_ptr_reg,
+				q->write_actual);
+		}
+	}
 	q->need_update = 0;
 
  exit_unlock: