From: Stefan Wahren wahrenst@gmx.net
commit 3b722da6672df8392f9c43d7c7e04bddd81d7e37 upstream.
The commit bebff81fb8b9 ("i2c: bcm2835: Model Divider in CCF") introduced a NULL pointer dereference on driver unload. It seems that we can't fetch the bus clock via devm_clk_get in bcm2835_i2c_remove. As an alternative approach store a pointer to the bus clock in the private driver structure.
Fixes: bebff81fb8b9 ("i2c: bcm2835: Model Divider in CCF") Signed-off-by: Stefan Wahren wahrenst@gmx.net Signed-off-by: Wolfram Sang wsa@the-dreams.de Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/i2c/busses/i2c-bcm2835.c | 17 ++++++++--------- 1 file changed, 8 insertions(+), 9 deletions(-)
--- a/drivers/i2c/busses/i2c-bcm2835.c +++ b/drivers/i2c/busses/i2c-bcm2835.c @@ -58,6 +58,7 @@ struct bcm2835_i2c_dev { struct i2c_adapter adapter; struct completion completion; struct i2c_msg *curr_msg; + struct clk *bus_clk; int num_msgs; u32 msg_err; u8 *msg_buf; @@ -404,7 +405,6 @@ static int bcm2835_i2c_probe(struct plat struct resource *mem, *irq; int ret; struct i2c_adapter *adap; - struct clk *bus_clk; struct clk *mclk; u32 bus_clk_rate;
@@ -427,11 +427,11 @@ static int bcm2835_i2c_probe(struct plat return PTR_ERR(mclk); }
- bus_clk = bcm2835_i2c_register_div(&pdev->dev, mclk, i2c_dev); + i2c_dev->bus_clk = bcm2835_i2c_register_div(&pdev->dev, mclk, i2c_dev);
- if (IS_ERR(bus_clk)) { + if (IS_ERR(i2c_dev->bus_clk)) { dev_err(&pdev->dev, "Could not register clock\n"); - return PTR_ERR(bus_clk); + return PTR_ERR(i2c_dev->bus_clk); }
ret = of_property_read_u32(pdev->dev.of_node, "clock-frequency", @@ -442,13 +442,13 @@ static int bcm2835_i2c_probe(struct plat bus_clk_rate = 100000; }
- ret = clk_set_rate_exclusive(bus_clk, bus_clk_rate); + ret = clk_set_rate_exclusive(i2c_dev->bus_clk, bus_clk_rate); if (ret < 0) { dev_err(&pdev->dev, "Could not set clock frequency\n"); return ret; }
- ret = clk_prepare_enable(bus_clk); + ret = clk_prepare_enable(i2c_dev->bus_clk); if (ret) { dev_err(&pdev->dev, "Couldn't prepare clock"); return ret; @@ -491,10 +491,9 @@ static int bcm2835_i2c_probe(struct plat static int bcm2835_i2c_remove(struct platform_device *pdev) { struct bcm2835_i2c_dev *i2c_dev = platform_get_drvdata(pdev); - struct clk *bus_clk = devm_clk_get(i2c_dev->dev, "div");
- clk_rate_exclusive_put(bus_clk); - clk_disable_unprepare(bus_clk); + clk_rate_exclusive_put(i2c_dev->bus_clk); + clk_disable_unprepare(i2c_dev->bus_clk);
free_irq(i2c_dev->irq, i2c_dev); i2c_del_adapter(&i2c_dev->adapter);