Messages in this thread | | | Date | Tue, 20 Jan 2015 08:05:20 +0100 | From | Lars-Peter Clausen <> | Subject | Re: [PATCH] i2c: drop ancient protection against sysfs refcounting issues |
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On 01/20/2015 02:41 AM, Greg Kroah-Hartman wrote: > On Mon, Jan 19, 2015 at 11:04:27PM +0000, Russell King - ARM Linux wrote: >> On Tue, Jan 20, 2015 at 03:01:42AM +0800, Greg Kroah-Hartman wrote: >>> On Mon, Jan 19, 2015 at 07:55:56PM +0100, Wolfram Sang wrote: >>>> diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c >>>> index 39d25a8cb1ad..15cc5902cf89 100644 >>>> --- a/drivers/i2c/i2c-core.c >>>> +++ b/drivers/i2c/i2c-core.c >>>> @@ -41,7 +41,6 @@ >>>> #include <linux/of_device.h> >>>> #include <linux/of_irq.h> >>>> #include <linux/clk/clk-conf.h> >>>> -#include <linux/completion.h> >>>> #include <linux/hardirq.h> >>>> #include <linux/irqflags.h> >>>> #include <linux/rwsem.h> >>>> @@ -1184,8 +1183,7 @@ EXPORT_SYMBOL_GPL(i2c_new_dummy); >>>> >>>> static void i2c_adapter_dev_release(struct device *dev) >>>> { >>>> - struct i2c_adapter *adap = to_i2c_adapter(dev); >>>> - complete(&adap->dev_released); >>>> + /* empty, but the driver core insists we need a release function */ >>> >>> Yeah, it does, but I hate to see this in "real" code as something is >>> probably wrong with it if it happens. >>> >>> Please move the rest of 'i2c_del_adapter' into the release function >>> (what was after the wait_for_completion() call), and then all should be >>> fine. >> >> Are you sure about that? Some drivers do this, eg, >> >> i2c_del_adapter(&drv_data->adapter); >> free_irq(drv_data->irq, drv_data); >> >> where drv_data was allocated using devm_kzalloc(), and so will be >> released when the ->remove callback (which calls the above >> i2c_del_adapter()) returns... freeing the embedded device struct. > > But that will fail today if the memory is freed in i2c_del_adapter(), so > there shouldn't be any change in logic here. > > Or am I missing something obvious?
The memory is not freed in i2c_del_adapter().
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