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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: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
This commit is contained in:
Masahiro Yamada 2016-09-01 20:46:28 +09:00 committed by Wolfram Sang
parent fbf8090b72
commit 4c91307ce9
1 changed files with 31 additions and 42 deletions
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73
drivers/i2c/busses/i2c-uniphier.c
View File

@ -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);