From mboxrd@z Thu Jan 1 00:00:00 1970 From: andy.shevchenko@gmail.com (Andy Shevchenko) Date: Wed, 21 Mar 2018 17:03:21 +0200 Subject: [PATCH v2] staging: bcm2835-audio: Release resources on module_exit() In-Reply-To: <1a59a938-0381-49f4-dfd9-c7a52bdb0eae@gmail.com> References: <63ee611d-9fd7-a67a-45aa-229cc4a83ed2@gmail.com> <20180313193414.11535-1-k.marinushkin@gmail.com> <1a59a938-0381-49f4-dfd9-c7a52bdb0eae@gmail.com> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Thu, Mar 15, 2018 at 7:57 AM, Kirill Marinushkin wrote: > On 03/13/18 22:23, Andy Shevchenko wrote: >> On Tue, Mar 13, 2018 at 9:34 PM, Kirill Marinushkin >> wrote: >>> 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. >> >>> 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? % 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. -- With Best Regards, Andy Shevchenko