[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>



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

[Neil Armstrong]

On 4/22/26 13:44, Xianwei Zhao via B4 Relay 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>
> ---
> 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,

Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>

Thanks,
Neil

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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

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