From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
	id S1752442AbcBVOz2 (ORCPT <rfc822;w@1wt.eu>);
	Mon, 22 Feb 2016 09:55:28 -0500
Received: from smtp-out-196.synserver.de ([212.40.185.196]:1216 "EHLO
	smtp-out-033.synserver.de" rhost-flags-OK-OK-OK-FAIL)
	by vger.kernel.org with ESMTP id S1751954AbcBVOz0 (ORCPT
	<rfc822;linux-kernel@vger.kernel.org>);
	Mon, 22 Feb 2016 09:55:26 -0500
X-SynServer-TrustedSrc: 1
X-SynServer-AuthUser: lars@metafoo.de
X-SynServer-PPID: 7825
Subject: Re: [alsa-devel] [PATCH v2] ASoC: wm9713: fix regmap free path
To: Robert Jarzmik <robert.jarzmik@free.fr>,
        Liam Girdwood <lgirdwood@gmail.com>, Mark Brown <broonie@kernel.org>,
        Jaroslav Kysela <perex@perex.cz>, Takashi Iwai <tiwai@suse.com>
References: <1455997470-12307-1-git-send-email-robert.jarzmik@free.fr>
Cc: alsa-devel@alsa-project.org, patches@opensource.wolfsonmicro.com,
        linux-kernel@vger.kernel.org
From: Lars-Peter Clausen <lars@metafoo.de>
Message-ID: <56C98DA3.4000701@metafoo.de>
Date: Sun, 21 Feb 2016 11:12:51 +0100
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101
 Icedove/38.5.0
MIME-Version: 1.0
In-Reply-To: <1455997470-12307-1-git-send-email-robert.jarzmik@free.fr>
Content-Type: text/plain; charset=windows-1252
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On 02/20/2016 08:44 PM, Robert Jarzmik wrote:
> In the conversion to regmap, I assumed that the 2 following functions
> was working symetrically:
>  - snd_soc_codec_init_regmap()
>  - snd_soc_codec_exit_regmap(codec)
> 
> As a mater of fact with the current code the regmap is freed twice
> because of the devm_() call:
> (mutex_lock) from (debugfs_remove_recursive+0x50/0x1d0)
> (debugfs_remove_recursive) from (regmap_debugfs_exit+0x1c/0xd4)
> (regmap_debugfs_exit) from (regmap_exit+0x28/0xc8)
> (regmap_exit) from (release_nodes+0x18c/0x204)
> (release_nodes) from (device_release+0x18/0x90)
> (device_release) from (kobject_release+0x90/0x1bc)
> (kobject_release) from (wm9713_soc_remove+0x1c/0x24)
> (wm9713_soc_remove) from (soc_remove_component+0x50/0x7c)
> (soc_remove_component) from (soc_remove_dai_links+0x118/0x228)
> (soc_remove_dai_links) from (snd_soc_register_card+0x4e4/0xdd4)
> (snd_soc_register_card) from (devm_snd_soc_register_card+0x34/0x70)
> 
> Fix this by removing the doubled regmap free.

The correct fix is to use the non devm variant of regmap_init_ac97() in this
case. Device managed functions should only be used from inside a struct
device probe function.

- Lars