From 4c91307ce9387519836e17482906ef0f698ea7d9 Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Thu, 1 Sep 2016 20:46:28 +0900 Subject: [PATCH] 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 Signed-off-by: Wolfram Sang --- drivers/i2c/busses/i2c-uniphier.c | 73 +++++++++++++------------------ 1 file changed, 31 insertions(+), 42 deletions(-) diff --git a/drivers/i2c/busses/i2c-uniphier.c b/drivers/i2c/busses/i2c-uniphier.c index d6e612a0e02a..56e92af46ddc 100644 --- a/drivers/i2c/busses/i2c-uniphier.c +++ b/drivers/i2c/busses/i2c-uniphier.c @@ -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); -- 2.20.1