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Commit 4ebe3a8f authored by Kamil Konieczny's avatar Kamil Konieczny Committed by Greg Kroah-Hartman
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PM / devfreq: exynos-bus: Correct clock enable sequence 



[ Upstream commit 2c2b20e0da89c76759ee28c6824413ab2fa3bfc6 ]

Regulators should be enabled before clocks to avoid h/w hang. This
require change in exynos_bus_probe() to move exynos_bus_parse_of()
after exynos_bus_parent_parse_of() and change in error handling.
Similar change is needed in exynos_bus_exit() where clock should be
disabled before regulators.

Signed-off-by: default avatarKamil Konieczny <k.konieczny@partner.samsung.com>
Acked-by: default avatarChanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: default avatarMyungJoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
parent d1e9aa3c

drivers/devfreq/exynos-bus.c

+17 −14
Original line number Diff line number Diff line
@@ -198,11 +198,10 @@ static void exynos_bus_exit(struct device *dev) 
	if (ret < 0)

		dev_warn(dev, "failed to disable the devfreq-event devices\n");



	if (bus->regulator)

		regulator_disable(bus->regulator);



	dev_pm_opp_of_remove_table(dev);

	clk_disable_unprepare(bus->clk);

	if (bus->regulator)

		regulator_disable(bus->regulator);

}



/*
@@ -391,6 +390,7 @@ static int exynos_bus_probe(struct platform_device *pdev) 
	struct exynos_bus *bus;

	int ret, max_state;

	unsigned long min_freq, max_freq;

	bool passive = false;



	if (!np) {

		dev_err(dev, "failed to find devicetree node\n");
@@ -404,27 +404,27 @@ static int exynos_bus_probe(struct platform_device *pdev) 
	bus->dev = &pdev->dev;

	platform_set_drvdata(pdev, bus);



	/* Parse the device-tree to get the resource information */

	ret = exynos_bus_parse_of(np, bus);

	if (ret < 0)

		return ret;



	profile = devm_kzalloc(dev, sizeof(*profile), GFP_KERNEL);

	if (!profile) {

		ret = -ENOMEM;

		goto err;

	}

	if (!profile)

		return -ENOMEM;



	node = of_parse_phandle(dev->of_node, "devfreq", 0);

	if (node) {

		of_node_put(node);

		goto passive;

		passive = true;

	} else {

		ret = exynos_bus_parent_parse_of(np, bus);

		if (ret < 0)

			return ret;

	}



	/* Parse the device-tree to get the resource information */

	ret = exynos_bus_parse_of(np, bus);

	if (ret < 0)

		goto err;

		goto err_reg;



	if (passive)

		goto passive;



	/* Initialize the struct profile and governor data for parent device */

	profile->polling_ms = 50;
@@ -514,6 +514,9 @@ static int exynos_bus_probe(struct platform_device *pdev) 
err:

	dev_pm_opp_of_remove_table(dev);

	clk_disable_unprepare(bus->clk);

err_reg:

	if (!passive)

		regulator_disable(bus->regulator);



	return ret;

}