Commit e72ce029 authored by Xianwei Zhao's avatar Xianwei Zhao Committed by Linus Walleij
Browse files

pinctrl: meson: amlogic-a4: fix deadlock issue 



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: 6e9be3ab ("pinctrl: Add driver support for Amlogic SoCs")
Signed-off-by: default avatarXianwei Zhao <xianwei.zhao@amlogic.com>
Reviewed-by: default avatarNeil Armstrong <neil.armstrong@linaro.org>
Signed-off-by: default avatarLinus Walleij <linusw@kernel.org>
parent d743c1ba

drivers/pinctrl/meson/pinctrl-amlogic-a4.c

+3 −3
Original line number Diff line number Diff line
@@ -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;