From: swarren@wwwdotorg•org (Stephen Warren)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH 07/10] pinctrl: remove mutex lock in groups show
Date: Thu, 18 Oct 2012 16:26:08 -0600 [thread overview]
Message-ID: <50808200.3080207@wwwdotorg.org> (raw)
In-Reply-To: <1350551224-12857-7-git-send-email-haojian.zhuang@gmail.com>
On 10/18/2012 03:07 AM, Haojian Zhuang wrote:
> Mutex is locked duplicatly by pinconf_groups_show() and
> pin_config_group_get(). It results dead lock. So avoid to lock mutex
> in pinconf_groups_show().
With this outer lock removed, how do we ensure that the pinctrl driver
that is being called into remains loaded? Does the existence of the
debugfs file ensure this, such that if it's open, the pinctrl driver
can't be removed?
Related, I wonder if much of the variable setup at the start of the
function shouldn't happen inside the lock instead of outside:
static int pinconf_groups_show(struct seq_file *s, void *what)
{
struct pinctrl_dev *pctldev = s->private;
const struct pinctrl_ops *pctlops = pctldev->desc->pctlops;
const struct pinconf_ops *ops = pctldev->desc->confops;
unsigned ngroups = pctlops->get_groups_count(pctldev);
since what if s->private is unregistered/destroyed while this function
is running?
next prev parent reply other threads:[~2012-10-18 22:26 UTC|newest]
Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-10-18 9:06 [PATCH 01/10] pinctrl: use postcore_initcall Haojian Zhuang
2012-10-18 9:06 ` [PATCH 02/10] ARM: mmp: select pinctrl driver Haojian Zhuang
2012-10-18 9:06 ` [PATCH 03/10] tty: pxa: configure pin Haojian Zhuang
2012-10-18 18:21 ` Linus Walleij
2012-10-18 22:20 ` Stephen Warren
2012-10-22 8:45 ` Linus Walleij
2012-10-22 20:26 ` Stephen Warren
2012-10-23 9:26 ` Linus Walleij
2012-10-23 9:37 ` Mark Brown
2012-10-23 9:59 ` Linus Walleij
2012-10-23 11:58 ` Mark Brown
2012-10-24 5:43 ` Linus Walleij
2012-10-18 9:06 ` [PATCH 04/10] i2c: pxa: configure pins Haojian Zhuang
2012-10-18 18:22 ` Linus Walleij
2012-10-18 9:06 ` [PATCH 05/10] i2c: pxa: use devm_kzalloc Haojian Zhuang
2012-10-18 22:27 ` Stephen Warren
2012-10-19 1:16 ` Haojian Zhuang
2012-10-18 9:07 ` [PATCH 06/10] pinctrl: single: support gpio request and free Haojian Zhuang
2012-10-19 22:37 ` Tony Lindgren
2012-10-18 9:07 ` [PATCH 07/10] pinctrl: remove mutex lock in groups show Haojian Zhuang
2012-10-18 18:29 ` Linus Walleij
2012-10-18 22:26 ` Stephen Warren [this message]
2012-10-22 8:53 ` Linus Walleij
2012-10-18 9:07 ` [PATCH 08/10] pinctrl: single: support pinconf generic Haojian Zhuang
2012-10-18 18:30 ` Linus Walleij
2012-10-18 22:29 ` Tony Lindgren
2012-10-19 2:23 ` Haojian Zhuang
2012-10-19 2:40 ` Tony Lindgren
2012-10-19 18:44 ` Tony Lindgren
2012-10-19 18:53 ` Tony Lindgren
2012-10-19 19:13 ` Tony Lindgren
2012-10-22 10:09 ` Haojian Zhuang
2012-10-22 17:09 ` Tony Lindgren
2012-10-25 23:43 ` Tony Lindgren
2012-10-26 1:47 ` Haojian Zhuang
2012-10-26 17:29 ` Tony Lindgren
2012-10-31 22:37 ` Haojian Zhuang
2012-10-18 9:07 ` [PATCH 09/10] ARM: dts: support pinctrl single in pxa910 Haojian Zhuang
2012-10-18 9:07 ` [PATCH 10/10] document: devicetree: bind pinconf in pinctrl single Haojian Zhuang
2012-10-19 22:40 ` Tony Lindgren
2012-10-18 18:20 ` [PATCH 01/10] pinctrl: use postcore_initcall Linus Walleij
2012-10-18 22:18 ` Stephen Warren
2012-10-18 22:28 ` Tony Lindgren
2012-10-19 2:16 ` Haojian Zhuang
2012-10-19 2:38 ` Tony Lindgren
2012-10-19 2:53 ` Haojian Zhuang
2012-10-19 17:41 ` Tony Lindgren
2012-10-19 2:24 ` Jean-Christophe PLAGNIOL-VILLARD
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