Re: [PATCH] i2c: drop ancient protection against sysfs refcounting issues
From: Lars-Peter Clausen
Date: Tue Jan 20 2015 - 02:03:32 EST
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().
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/