linux-kernel - [PATCH v7 2/3] clk: clk-max77686: Clean clkdev lookup leak and use devm

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Date:   Fri, 7 Dec 2018 13:10:15 +0200
From:   Matti Vaittinen <matti.vaittinen@...rohmeurope.com>
To:     matti.vaittinen@...rohmeurope.com, mazziesaccount@...il.com,
        corbet@....net, cw00.choi@...sung.com, krzk@...nel.org,
        b.zolnierkie@...sung.com, mturquette@...libre.com,
        sboyd@...nel.org, linux@...linux.org.uk, pombredanne@...b.com,
        sre@...nel.org, vkoul@...nel.org, linux@...ck-us.net, pavel@....cz,
        sjhuang@...vatar.ai, andrew.smirnov@...il.com,
        djkurtz@...omium.org, akshu.agrawal@....com,
        rafael.j.wysocki@...el.com, linux-doc@...r.kernel.org,
        linux-kernel@...r.kernel.org, linux-clk@...r.kernel.org,
        linux-arm-kernel@...ts.infradead.org
Subject: [PATCH v7 2/3] clk: clk-max77686: Clean clkdev lookup leak and use
 devm

clk-max77686 never clean clkdev lookup at remove. This can cause
oops if clk-max77686 is removed and inserted again. Fix leak by
using new devm clkdev lookup registration. Simplify also error
path by using new devm_of_clk_add_hw_provider.

Signed-off-by: Matti Vaittinen <matti.vaittinen@...rohmeurope.com>
Reviewed-by: Krzysztof Kozlowski <krzk@...nel.org>
---
Please note that the patch #2 requires this change to work correctly:
https://git.kernel.org/pub/scm/linux/kernel/git/clk/linux.git/commit/?h=clk-next&id=05502bf9eb7a7297f5fa6f1d17b169b3d5b53570

 drivers/clk/clk-max77686.c | 28 ++++++----------------------
 1 file changed, 6 insertions(+), 22 deletions(-)

diff --git a/drivers/clk/clk-max77686.c b/drivers/clk/clk-max77686.c
index 22c937644c93..3727d5472450 100644
--- a/drivers/clk/clk-max77686.c
+++ b/drivers/clk/clk-max77686.c
@@ -235,8 +235,9 @@ static int max77686_clk_probe(struct platform_device *pdev)
 			return ret;
 		}
 
-		ret = clk_hw_register_clkdev(&max_clk_data->hw,
-					     max_clk_data->clk_idata.name, NULL);
+		ret = devm_clk_hw_register_clkdev(dev, &max_clk_data->hw,
+						  max_clk_data->clk_idata.name,
+						  NULL);
 		if (ret < 0) {
 			dev_err(dev, "Failed to clkdev register: %d\n", ret);
 			return ret;
@@ -244,8 +245,8 @@ static int max77686_clk_probe(struct platform_device *pdev)
 	}
 
 	if (parent->of_node) {
-		ret = of_clk_add_hw_provider(parent->of_node, of_clk_max77686_get,
-					     drv_data);
+		ret = devm_of_clk_add_hw_provider(dev, of_clk_max77686_get,
+						  drv_data);
 
 		if (ret < 0) {
 			dev_err(dev, "Failed to register OF clock provider: %d\n",
@@ -261,27 +262,11 @@ static int max77686_clk_probe(struct platform_device *pdev)
 					 1 << MAX77802_CLOCK_LOW_JITTER_SHIFT);
 		if (ret < 0) {
 			dev_err(dev, "Failed to config low-jitter: %d\n", ret);
-			goto remove_of_clk_provider;
+			return ret;
 		}
 	}
 
 	return 0;
-
-remove_of_clk_provider:
-	if (parent->of_node)
-		of_clk_del_provider(parent->of_node);
-
-	return ret;
-}
-
-static int max77686_clk_remove(struct platform_device *pdev)
-{
-	struct device *parent = pdev->dev.parent;
-
-	if (parent->of_node)
-		of_clk_del_provider(parent->of_node);
-
-	return 0;
 }
 
 static const struct platform_device_id max77686_clk_id[] = {
@@ -297,7 +282,6 @@ static struct platform_driver max77686_clk_driver = {
 		.name  = "max77686-clk",
 	},
 	.probe = max77686_clk_probe,
-	.remove = max77686_clk_remove,
 	.id_table = max77686_clk_id,
 };
 
-- 
2.14.3