From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joachim Eastwood Subject: [PATCH 1/3] pinctrl: core: create unlocked version of pinctrl_find_gpio_range_from_pin Date: Sat, 20 Feb 2016 23:51:54 +0100 Message-ID: <1456008716-6236-2-git-send-email-manabian@gmail.com> References: <1456008716-6236-1-git-send-email-manabian@gmail.com> Return-path: Received: from mail-lf0-f41.google.com ([209.85.215.41]:33811 "EHLO mail-lf0-f41.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753038AbcBTWwS (ORCPT ); Sat, 20 Feb 2016 17:52:18 -0500 Received: by mail-lf0-f41.google.com with SMTP id j78so74018629lfb.1 for ; Sat, 20 Feb 2016 14:52:17 -0800 (PST) In-Reply-To: <1456008716-6236-1-git-send-email-manabian@gmail.com> Sender: linux-gpio-owner@vger.kernel.org List-Id: linux-gpio@vger.kernel.org To: linus.walleij@linaro.org Cc: Joachim Eastwood , linux-gpio@vger.kernel.org pinctrl_find_gpio_range_from_pin takes the pctldev->mutex but so does pinconf_pins_show and this will cause a deadlock if pinctrl_find_gpio_range_from_pin is used in .pin_config_get callback. Create an unlocked version of pinctrl_find_gpio_range_from_pin to allow pin to gpio lookup to be used from pinconf_pins_show. Signed-off-by: Joachim Eastwood --- Hi Linus, Here is traceback I got before I added this: [ 161.370000] cat D 281b5275 0 23 1 0x00000000 [ 161.370000] [<281b5275>] (__schedule) from [<281b5479>] (schedule+0x29/0x5c) [ 161.370000] [<281b5479>] (schedule) from [<281b54bb>] (schedule_preempt_disabled+0xf/0x18) [ 161.370000] [<281b54bb>] (schedule_preempt_disabled) from [<281b6401>] (__mutex_lock_slowpath+0x45/0xf8) [ 161.370000] [<281b6401>] (__mutex_lock_slowpath) from [<280b5ddb>] (pinctrl_find_gpio_range_from_pin+0x13/0x68) [ 161.370000] [<280b5ddb>] (pinctrl_find_gpio_range_from_pin) from [<280b8da9>] (lpc18xx_pconf_get+0x95/0x204) [ 161.370000] [<280b8da9>] (lpc18xx_pconf_get) from [<280b827b>] (pinconf_generic_dump_one+0xbb/0xcc) [ 161.370000] [<280b827b>] (pinconf_generic_dump_one) from [<280b8337>] (pinconf_generic_dump_pins+0x4f/0x54) [ 161.370000] [<280b8337>] (pinconf_generic_dump_pins) from [<280b7b01>] (pinconf_pins_show+0x8d/0xc0) [ 161.370000] [<280b7b01>] (pinconf_pins_show) from [<28068fb7>] (seq_read+0x7b/0x2bc) [ 161.370000] [<28068fb7>] (seq_read) from [<280547f3>] (SyS_read+0x2b/0x68) [ 161.370000] [<280547f3>] (SyS_read) from [<28008c61>] (ret_fast_syscall+0x1/0x4a) drivers/pinctrl/core.c | 25 ++++++++++++++++++------- drivers/pinctrl/core.h | 4 ++++ 2 files changed, 22 insertions(+), 7 deletions(-) diff --git a/drivers/pinctrl/core.c b/drivers/pinctrl/core.c index 2686a4450dfc..0c2cb883b18a 100644 --- a/drivers/pinctrl/core.c +++ b/drivers/pinctrl/core.c @@ -487,12 +487,11 @@ EXPORT_SYMBOL_GPL(pinctrl_get_group_pins); * @pin: a controller-local number to find the range for */ struct pinctrl_gpio_range * -pinctrl_find_gpio_range_from_pin(struct pinctrl_dev *pctldev, - unsigned int pin) +__pinctrl_find_gpio_range_from_pin(struct pinctrl_dev *pctldev, + unsigned int pin) { struct pinctrl_gpio_range *range; - mutex_lock(&pctldev->mutex); /* Loop over the ranges */ list_for_each_entry(range, &pctldev->gpio_ranges, node) { /* Check if we're in the valid range */ @@ -500,15 +499,27 @@ pinctrl_find_gpio_range_from_pin(struct pinctrl_dev *pctldev, int a; for (a = 0; a < range->npins; a++) { if (range->pins[a] == pin) - goto out; + return range; } } else if (pin >= range->pin_base && pin < range->pin_base + range->npins) - goto out; + return range; } - range = NULL; -out: + + return NULL; +} +EXPORT_SYMBOL_GPL(__pinctrl_find_gpio_range_from_pin); + +struct pinctrl_gpio_range * +pinctrl_find_gpio_range_from_pin(struct pinctrl_dev *pctldev, + unsigned int pin) +{ + struct pinctrl_gpio_range *range; + + mutex_lock(&pctldev->mutex); + range = __pinctrl_find_gpio_range_from_pin(pctldev, pin); mutex_unlock(&pctldev->mutex); + return range; } EXPORT_SYMBOL_GPL(pinctrl_find_gpio_range_from_pin); diff --git a/drivers/pinctrl/core.h b/drivers/pinctrl/core.h index b24ea846c867..99bd8428542a 100644 --- a/drivers/pinctrl/core.h +++ b/drivers/pinctrl/core.h @@ -182,6 +182,10 @@ static inline struct pin_desc *pin_desc_get(struct pinctrl_dev *pctldev, return radix_tree_lookup(&pctldev->pin_desc_tree, pin); } +extern struct pinctrl_gpio_range * +__pinctrl_find_gpio_range_from_pin(struct pinctrl_dev *pctldev, + unsigned int pin); + int pinctrl_register_map(struct pinctrl_map const *maps, unsigned num_maps, bool dup); void pinctrl_unregister_map(struct pinctrl_map const *map); -- 1.8.0