[PATCH] pinctrl: meson: amlogic-a4: fix deadlock issue

[PATCH] pinctrl: meson: amlogic-a4: fix deadlock issue

[Xianwei Zhao via B4 Relay]

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>

Re: [PATCH] pinctrl: meson: amlogic-a4: fix deadlock issue

[Linus Walleij]

On Wed, Apr 22, 2026 at 1:44 PM Xianwei Zhao via B4 Relay
<devnull+xianwei.zhao.amlogic.com@kernel.org> wrote:

> 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>

Patch applied for fixes!

Yours,
Linus Walleij