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From: Xianwei Zhao via B4 Relay <devnull+xianwei.zhao.amlogic.com@kernel.org>
To: Linus Walleij <linusw@kernel.org>,
	 Neil Armstrong <neil.armstrong@linaro.org>,
	 Kevin Hilman <khilman@baylibre.com>,
	Jerome Brunet <jbrunet@baylibre.com>,
	 Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Cc: linux-amlogic@lists.infradead.org, linux-gpio@vger.kernel.org,
	 linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org,
	 Xianwei Zhao <xianwei.zhao@amlogic.com>
Subject: [PATCH] pinctrl: meson: amlogic-a4: fix deadlock issue
Date: Wed, 22 Apr 2026 11:44:13 +0000	[thread overview]
Message-ID: <20260422-fix-pinconf-v1-1-abb4d2e0da55@amlogic.com> (raw)

From: Xianwei Zhao <xianwei.zhao@amlogic.com>

Accessing the pinconf-pins sysfs node may deadlock.

pinconf_pins_show() holds pctldev->mutex, and the platform driver
calls pinctrl_find_gpio_range_from_pin(), which tries to acquire
the same mutex again, leading to a deadlock.

Use pinctrl_find_gpio_range_from_pin_nolock() to fix this issue.

Fixes: 6e9be3abb78c ("pinctrl: Add driver support for Amlogic SoCs")
Signed-off-by: Xianwei Zhao <xianwei.zhao@amlogic.com>
---
Fix deadlock issue.
---
 drivers/pinctrl/meson/pinctrl-amlogic-a4.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/pinctrl/meson/pinctrl-amlogic-a4.c b/drivers/pinctrl/meson/pinctrl-amlogic-a4.c
index e2293a872dcb..35d27626a336 100644
--- a/drivers/pinctrl/meson/pinctrl-amlogic-a4.c
+++ b/drivers/pinctrl/meson/pinctrl-amlogic-a4.c
@@ -292,7 +292,7 @@ static int aml_calc_reg_and_bit(struct pinctrl_gpio_range *range,
 static int aml_pinconf_get_pull(struct aml_pinctrl *info, unsigned int pin)
 {
 	struct pinctrl_gpio_range *range =
-			 pinctrl_find_gpio_range_from_pin(info->pctl, pin);
+			 pinctrl_find_gpio_range_from_pin_nolock(info->pctl, pin);
 	struct aml_gpio_bank *bank = gpio_chip_to_bank(range->gc);
 	unsigned int reg, bit, val;
 	int ret, conf;
@@ -326,7 +326,7 @@ static int aml_pinconf_get_drive_strength(struct aml_pinctrl *info,
 					  u16 *drive_strength_ua)
 {
 	struct pinctrl_gpio_range *range =
-			 pinctrl_find_gpio_range_from_pin(info->pctl, pin);
+			 pinctrl_find_gpio_range_from_pin_nolock(info->pctl, pin);
 	struct aml_gpio_bank *bank = gpio_chip_to_bank(range->gc);
 	unsigned int reg, bit;
 	unsigned int val;
@@ -365,7 +365,7 @@ static int aml_pinconf_get_gpio_bit(struct aml_pinctrl *info,
 				    unsigned int reg_type)
 {
 	struct pinctrl_gpio_range *range =
-			 pinctrl_find_gpio_range_from_pin(info->pctl, pin);
+			 pinctrl_find_gpio_range_from_pin_nolock(info->pctl, pin);
 	struct aml_gpio_bank *bank = gpio_chip_to_bank(range->gc);
 	unsigned int reg, bit, val;
 	int ret;

---
base-commit: bd7fd288490c64835a74c05e631c102ce056d5e1
change-id: 20260422-fix-pinconf-42be1cc2f5af

Best regards,
-- 
Xianwei Zhao <xianwei.zhao@amlogic.com>




             reply	other threads:[~2026-04-22 11:44 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-04-22 11:44 Xianwei Zhao via B4 Relay [this message]
2026-04-28  9:50 ` [PATCH] pinctrl: meson: amlogic-a4: fix deadlock issue Linus Walleij

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