Re: [PATCH] ACPI: Add GPIO-signaled event emulator.

Mika Westerberg
2014-08-21T14:54:05Z

On Thu, Aug 21, 2014 at 04:39:46PM +0200, Tomasz Nowicki wrote:
> >>+{
> >>+ struct gpio_pin_data *pin_data, *temp;
> >>+
> >>+ list_for_each_entry_safe(pin_data, temp, &pin_data_list, list)
> >>+ kfree(pin_data);
> >
> >I suppose you want to first remove the directory entries and then the
> >pin data. Otherwise if you get pre-empted at this point and someone
> >tries to use your debugfs files, bad things might happen.
> Good catch!
>
> >
> >>+
> >>+ debugfs_remove_recursive(acpi_evt_debugfs_dir);
> >
> >Since this already removes everything below this dentry, why do you need
> >to store the pointer in gpio_pin_parent_data?
> Not sure I got the question.
>
> GPIO device instance (debugfs dir) is parent for all its pins (debugfs
> nodes). I am using gpio_pin_parent_data as container to pass info for all
> children so I can create debugfs node inside of parent related debugfs dir.
>
> pin_data_list, however, is used to keep pointers to allocated memory (one
> for each pins). debugfs_remove_recursive won't free it.

Yes but it removes the debugfs entries below so you don't need to store
the children debugfs dentries.