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Commit 4c91307c authored by Masahiro Yamada's avatar Masahiro Yamada Committed by Wolfram Sang
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i2c: uniphier: avoid WARN_ON() of clk_disable() in failure path 



If clk_prepare_enable() fails, clk_disable_unprepare() is called in
the failure path, where the enable_count is still zero, so it hits
WARN_ON(core->enable_count == 0) in the clk_core_disable().

To fix this, make the clock setting more linear in the probe function
so that it can exploit "goto err" in case of error.

Signed-off-by: default avatarMasahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: default avatarWolfram Sang <wsa@the-dreams.de>
parent fbf8090b

drivers/i2c/busses/i2c-uniphier.c

+31 −42
Original line number Diff line number Diff line
@@ -316,50 +316,15 @@ static struct i2c_bus_recovery_info uniphier_i2c_bus_recovery_info = { 
	.unprepare_recovery = uniphier_i2c_unprepare_recovery,

};



static int uniphier_i2c_clk_init(struct device *dev,

				 struct uniphier_i2c_priv *priv)

static void uniphier_i2c_hw_init(struct uniphier_i2c_priv *priv,

				 u32 bus_speed, unsigned long clk_rate)

{

	struct device_node *np = dev->of_node;

	unsigned long clk_rate;

	u32 bus_speed;

	int ret;



	if (of_property_read_u32(np, "clock-frequency", &bus_speed))

		bus_speed = UNIPHIER_I2C_DEFAULT_SPEED;



	if (!bus_speed) {

		dev_err(dev, "clock-frequency should not be zero\n");

		return -EINVAL;

	}



	if (bus_speed > UNIPHIER_I2C_MAX_SPEED)

		bus_speed = UNIPHIER_I2C_MAX_SPEED;



	/* Get input clk rate through clk driver */

	priv->clk = devm_clk_get(dev, NULL);

	if (IS_ERR(priv->clk)) {

		dev_err(dev, "failed to get clock\n");

		return PTR_ERR(priv->clk);

	}



	ret = clk_prepare_enable(priv->clk);

	if (ret)

		return ret;



	clk_rate = clk_get_rate(priv->clk);

	if (!clk_rate) {

		dev_err(dev, "input clock rate should not be zero\n");

		return -EINVAL;

	}



	uniphier_i2c_reset(priv, true);



	writel((clk_rate / bus_speed / 2 << 16) | (clk_rate / bus_speed),

	       priv->membase + UNIPHIER_I2C_CLK);



	uniphier_i2c_reset(priv, false);



	return 0;

}



static int uniphier_i2c_probe(struct platform_device *pdev)
@@ -367,8 +332,9 @@ static int uniphier_i2c_probe(struct platform_device *pdev) 
	struct device *dev = &pdev->dev;

	struct uniphier_i2c_priv *priv;

	struct resource *regs;

	int irq;

	int ret;

	u32 bus_speed;

	unsigned long clk_rate;

	int irq, ret;



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

	if (!priv)
@@ -385,6 +351,31 @@ static int uniphier_i2c_probe(struct platform_device *pdev) 
		return irq;

	}



	if (of_property_read_u32(dev->of_node, "clock-frequency", &bus_speed))

		bus_speed = UNIPHIER_I2C_DEFAULT_SPEED;



	if (!bus_speed || bus_speed > UNIPHIER_I2C_MAX_SPEED) {

		dev_err(dev, "invalid clock-frequency %d\n", bus_speed);

		return -EINVAL;

	}



	priv->clk = devm_clk_get(dev, NULL);

	if (IS_ERR(priv->clk)) {

		dev_err(dev, "failed to get clock\n");

		return PTR_ERR(priv->clk);

	}



	ret = clk_prepare_enable(priv->clk);

	if (ret)

		return ret;



	clk_rate = clk_get_rate(priv->clk);

	if (!clk_rate) {

		dev_err(dev, "input clock rate should not be zero\n");

		ret = -EINVAL;

		goto err;

	}



	init_completion(&priv->comp);

	priv->adap.owner = THIS_MODULE;

	priv->adap.algo = &uniphier_i2c_algo;
@@ -395,9 +386,7 @@ static int uniphier_i2c_probe(struct platform_device *pdev) 
	i2c_set_adapdata(&priv->adap, priv);

	platform_set_drvdata(pdev, priv);



	ret = uniphier_i2c_clk_init(dev, priv);

	if (ret)

		goto err;

	uniphier_i2c_hw_init(priv, bus_speed, clk_rate);



	ret = devm_request_irq(dev, irq, uniphier_i2c_interrupt, 0, pdev->name,

			       priv);