[PATCH v2] staging: bcm2835-audio: Release resources on module_exit()

On 03/21/18 16:03, Andy Shevchenko wrote:

On Thu, Mar 15, 2018 at 7:57 AM, Kirill Marinushkin
[off-list ref] wrote:

quoted

On 03/13/18 22:23, Andy Shevchenko wrote:

quoted

On Tue, Mar 13, 2018 at 9:34 PM, Kirill Marinushkin
[off-list ref] wrote:

quoted

In the current implementation, `rmmod snd_bcm2835` does not release
resources properly. It causes an oops when trying to list sound devices.

This commit fixes it.

Nice catch!

See my comments below.

quoted

 static void snd_devm_unregister_child(struct device *dev, void *res)
 {
        struct device *childdev = *(struct device **)res;
+       struct bcm2835_chip *chip = dev_get_drvdata(childdev);
+       struct snd_card *card = chip->card;
+
+       snd_card_free(card);
+       dev_set_drvdata(childdev, NULL);

AFAIU this is done by device core.

Maybe you are right. But I don't know, which function in the device core does it.
It is safe to have this line. So, I suggest to keep it.

Please, remove.
If you don't know, perhaps you need to spend more time on doing homework?

You are right, I actually should pay more attention to this detail.
I will remove this line and send as a patch v3

% git grep -n -w dev_set_drvdata -- drivers/base/dd.c
drivers/base/dd.c:469:          dev_set_drvdata(dev, NULL);
drivers/base/dd.c:499:  dev_set_drvdata(dev, NULL);
drivers/base/dd.c:902:          dev_set_drvdata(dev, NULL);

Last one is the point of your interest.