From mboxrd@z Thu Jan 1 00:00:00 1970 From: k.marinushkin@gmail.com (Kirill Marinushkin) Date: Wed, 21 Mar 2018 17:58:06 +0100 Subject: [PATCH v2] staging: bcm2835-audio: Release resources on module_exit() In-Reply-To: References: <63ee611d-9fd7-a67a-45aa-229cc4a83ed2@gmail.com> <20180313193414.11535-1-k.marinushkin@gmail.com> <1a59a938-0381-49f4-dfd9-c7a52bdb0eae@gmail.com> Message-ID: <15cc84cc-a887-7473-d64c-00c23e930e0d@gmail.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 03/21/18 16:03, Andy Shevchenko wrote: > 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? 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. >