drivers: net: xgene: Check for IS_ERR rather than NULL for clock.

This patches fixes the code to check for IS_ERR rather
than NULL for clock interface.
Signed-off-by: Iyappan Subramanian <isubramanian@apm.com>
Signed-off-by: Suman Tripathi <stripathi@apm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/apm/xgene/xgene_enet_hw.c

@@ -610,7 +610,7 @@ static int xgene_enet_reset(struct xgene_enet_pdata *pdata)
 	if (!xgene_ring_mgr_init(pdata))
 		return -ENODEV;
 
-	if (pdata->clk) {
+	if (!IS_ERR(pdata->clk)) {
 		clk_prepare_enable(pdata->clk);
 		clk_disable_unprepare(pdata->clk);
 		clk_prepare_enable(pdata->clk);
@@ -629,7 +629,8 @@ static int xgene_enet_reset(struct xgene_enet_pdata *pdata)
 
 static void xgene_gport_shutdown(struct xgene_enet_pdata *pdata)
 {
-	clk_disable_unprepare(pdata->clk);
+	if (!IS_ERR(pdata->clk))
+		clk_disable_unprepare(pdata->clk);
 }
 
 static int xgene_enet_mdio_read(struct mii_bus *bus, int mii_id, int regnum)

drivers/net/ethernet/apm/xgene/xgene_enet_main.c

@@ -1036,7 +1036,7 @@ static int xgene_enet_get_resources(struct xgene_enet_pdata *pdata)
 	pdata->clk = devm_clk_get(&pdev->dev, NULL);
 	if (IS_ERR(pdata->clk)) {
 		/* Firmware may have set up the clock already. */
-		pdata->clk = NULL;
+		dev_info(dev, "clocks have been setup already\n");
 	}
 
 	if (pdata->phy_mode != PHY_INTERFACE_MODE_XGMII)

drivers/net/ethernet/apm/xgene/xgene_enet_sgmac.c

@@ -334,9 +334,11 @@ static int xgene_enet_reset(struct xgene_enet_pdata *p)
 	if (!xgene_ring_mgr_init(p))
 		return -ENODEV;
 
-	clk_prepare_enable(p->clk);
-	clk_disable_unprepare(p->clk);
-	clk_prepare_enable(p->clk);
+	if (!IS_ERR(p->clk)) {
+		clk_prepare_enable(p->clk);
+		clk_disable_unprepare(p->clk);
+		clk_prepare_enable(p->clk);
+	}
 
 	xgene_enet_ecc_init(p);
 	xgene_enet_config_ring_if_assoc(p);
@@ -369,7 +371,8 @@ static void xgene_enet_cle_bypass(struct xgene_enet_pdata *p,
 
 static void xgene_enet_shutdown(struct xgene_enet_pdata *p)
 {
-	clk_disable_unprepare(p->clk);
+	if (!IS_ERR(p->clk))
+		clk_disable_unprepare(p->clk);
 }
 
 static void xgene_enet_link_state(struct work_struct *work)

drivers/net/ethernet/apm/xgene/xgene_enet_xgmac.c

@@ -256,9 +256,11 @@ static int xgene_enet_reset(struct xgene_enet_pdata *pdata)
 	if (!xgene_ring_mgr_init(pdata))
 		return -ENODEV;
 
-	clk_prepare_enable(pdata->clk);
-	clk_disable_unprepare(pdata->clk);
-	clk_prepare_enable(pdata->clk);
+	if (!IS_ERR(pdata->clk)) {
+		clk_prepare_enable(pdata->clk);
+		clk_disable_unprepare(pdata->clk);
+		clk_prepare_enable(pdata->clk);
+	}
 
 	xgene_enet_ecc_init(pdata);
 	xgene_enet_config_ring_if_assoc(pdata);
@@ -285,7 +287,8 @@ static void xgene_enet_xgcle_bypass(struct xgene_enet_pdata *pdata,
 
 static void xgene_enet_shutdown(struct xgene_enet_pdata *pdata)
 {
-	clk_disable_unprepare(pdata->clk);
+	if (!IS_ERR(pdata->clk))
+		clk_disable_unprepare(pdata->clk);
 }
 
 static void xgene_enet_link_state(struct work_struct *work)