[PATCH net v3 2/2] net: bcmasp: fix double disable of clk

[justin.chen@broadcom.com]

From: Justin Chen <justin.chen@broadcom.com>

Switch to devm_clk_get_optional() so we can manage the clock ourselves.
We dynamically control the clocks depending on the state of the interface
for power savings. The default state is clock disabled, so unbinding the
driver causes a double disable.

Fixes: 490cb412007d ("net: bcmasp: Add support for ASP2.0 Ethernet controller")
Signed-off-by: Justin Chen <justin.chen@broadcom.com>
Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
---
v3
- Do not disable clock until probe is entirely done to avoid
  double disable on error path.

v2
- Split into two patches.
- Add error path to disable clock if we fail during probe.

 drivers/net/ethernet/broadcom/asp2/bcmasp.c | 33 ++++++++++++++-------
 1 file changed, 23 insertions(+), 10 deletions(-)

diff --git a/drivers/net/ethernet/broadcom/asp2/bcmasp.c b/drivers/net/ethernet/broadcom/asp2/bcmasp.c
index 2034a1593db7..972474893a6b 100644
--- a/drivers/net/ethernet/broadcom/asp2/bcmasp.c
+++ b/drivers/net/ethernet/broadcom/asp2/bcmasp.c
@@ -1249,7 +1249,7 @@ static int bcmasp_probe(struct platform_device *pdev)
 	if (priv->irq <= 0)
 		return -EINVAL;
 
-	priv->clk = devm_clk_get_optional_enabled(dev, "sw_asp");
+	priv->clk = devm_clk_get_optional(dev, "sw_asp");
 	if (IS_ERR(priv->clk))
 		return dev_err_probe(dev, PTR_ERR(priv->clk),
 				     "failed to request clock\n");
@@ -1277,6 +1277,10 @@ static int bcmasp_probe(struct platform_device *pdev)
 
 	bcmasp_set_pdata(priv, pdata);
 
+	ret = clk_prepare_enable(priv->clk);
+	if (ret)
+		return dev_err_probe(dev, ret, "failed to start clock\n");
+
 	/* Enable all clocks to ensure successful probing */
 	bcmasp_core_clock_set(priv, ASP_CTRL_CLOCK_CTRL_ASP_ALL_DISABLE, 0);
 
@@ -1288,8 +1292,10 @@ static int bcmasp_probe(struct platform_device *pdev)
 
 	ret = devm_request_irq(&pdev->dev, priv->irq, bcmasp_isr, 0,
 			       pdev->name, priv);
-	if (ret)
-		return dev_err_probe(dev, ret, "failed to request ASP interrupt: %d", ret);
+	if (ret) {
+		dev_err(dev, "Failed to request ASP interrupt: %d", ret);
+		goto err_clock_disable;
+	}
 
 	/* Register mdio child nodes */
 	of_platform_populate(dev->of_node, bcmasp_mdio_of_match, NULL, dev);
@@ -1301,13 +1307,17 @@ static int bcmasp_probe(struct platform_device *pdev)
 
 	priv->mda_filters = devm_kcalloc(dev, priv->num_mda_filters,
 					 sizeof(*priv->mda_filters), GFP_KERNEL);
-	if (!priv->mda_filters)
-		return -ENOMEM;
+	if (!priv->mda_filters) {
+		ret = -ENOMEM;
+		goto err_clock_disable;
+	}
 
 	priv->net_filters = devm_kcalloc(dev, priv->num_net_filters,
 					 sizeof(*priv->net_filters), GFP_KERNEL);
-	if (!priv->net_filters)
-		return -ENOMEM;
+	if (!priv->net_filters) {
+		ret = -ENOMEM;
+		goto err_clock_disable;
+	}
 
 	bcmasp_core_init_filters(priv);
 
@@ -1316,7 +1326,8 @@ static int bcmasp_probe(struct platform_device *pdev)
 	ports_node = of_find_node_by_name(dev->of_node, "ethernet-ports");
 	if (!ports_node) {
 		dev_warn(dev, "No ports found\n");
-		return -EINVAL;
+		ret = -EINVAL;
+		goto err_clock_disable;
 	}
 
 	i = 0;
@@ -1338,8 +1349,6 @@ static int bcmasp_probe(struct platform_device *pdev)
 	 */
 	bcmasp_core_clock_set(priv, 0, ASP_CTRL_CLOCK_CTRL_ASP_ALL_DISABLE);
 
-	clk_disable_unprepare(priv->clk);
-
 	/* Now do the registration of the network ports which will take care
 	 * of managing the clock properly.
 	 */
@@ -1352,12 +1361,16 @@ static int bcmasp_probe(struct platform_device *pdev)
 		count++;
 	}
 
+	clk_disable_unprepare(priv->clk);
+
 	dev_info(dev, "Initialized %d port(s)\n", count);
 
 	return ret;
 
 err_cleanup:
 	bcmasp_remove_intfs(priv);
+err_clock_disable:
+	clk_disable_unprepare(priv->clk);
 
 	return ret;
 }
-- 
2.34.1