From ae42f9288846353982e2eab181fb41e7fd8bf60f Mon Sep 17 00:00:00 2001 From: Shreeya Patel Date: Thu, 17 Feb 2022 01:56:55 +0530 Subject: gpio: Return EPROBE_DEFER if gc->to_irq is NULL We are racing the registering of .to_irq when probing the i2c driver. This results in random failure of touchscreen devices. Following explains the race condition better. [gpio driver] gpio driver registers gpio chip [gpio consumer] gpio is acquired [gpio consumer] gpiod_to_irq() fails with -ENXIO [gpio driver] gpio driver registers irqchip gpiod_to_irq works at this point, but -ENXIO is fatal We could see the following errors in dmesg logs when gc->to_irq is NULL [2.101857] i2c_hid i2c-FTS3528:00: HID over i2c has not been provided an Int IRQ [2.101953] i2c_hid: probe of i2c-FTS3528:00 failed with error -22 To avoid this situation, defer probing until to_irq is registered. Returning -EPROBE_DEFER would be the first step towards avoiding the failure of devices due to the race in registration of .to_irq. Final solution to this issue would be to avoid using gc irq members until they are fully initialized. This issue has been reported many times in past and people have been using workarounds like changing the pinctrl_amd to built-in instead of loading it as a module or by adding a softdep for pinctrl_amd into the config file. BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=209413 Reviewed-by: Linus Walleij Reviewed-by: Andy Shevchenko Reported-by: kernel test robot Signed-off-by: Shreeya Patel Signed-off-by: Bartosz Golaszewski --- drivers/gpio/gpiolib.c | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'drivers/gpio/gpiolib.c') diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 3859911b61e9..a3d14277f17c 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -3147,6 +3147,16 @@ int gpiod_to_irq(const struct gpio_desc *desc) return retirq; } +#ifdef CONFIG_GPIOLIB_IRQCHIP + if (gc->irq.chip) { + /* + * Avoid race condition with other code, which tries to lookup + * an IRQ before the irqchip has been properly registered, + * i.e. while gpiochip is still being brought up. + */ + return -EPROBE_DEFER; + } +#endif return -ENXIO; } EXPORT_SYMBOL_GPL(gpiod_to_irq); -- cgit v1.2.3-70-g09d2 From fc328a7d1fcce263db0b046917a66f3aa6e68719 Mon Sep 17 00:00:00 2001 From: Marcelo Roberto Jimenez Date: Mon, 7 Mar 2022 10:57:24 +0100 Subject: gpio: Revert regression in sysfs-gpio (gpiolib.c) Some GPIO lines have stopped working after the patch commit 2ab73c6d8323f ("gpio: Support GPIO controllers without pin-ranges") And this has supposedly been fixed in the following patches commit 89ad556b7f96a ("gpio: Avoid using pin ranges with !PINCTRL") commit 6dbbf84603961 ("gpiolib: Don't free if pin ranges are not defined") But an erratic behavior where some GPIO lines work while others do not work has been introduced. This patch reverts those changes so that the sysfs-gpio interface works properly again. Signed-off-by: Marcelo Roberto Jimenez Signed-off-by: Bartosz Golaszewski --- drivers/gpio/gpiolib.c | 10 ---------- 1 file changed, 10 deletions(-) (limited to 'drivers/gpio/gpiolib.c') diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index a3d14277f17c..005642068c0b 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -1701,11 +1701,6 @@ static inline void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gc) */ int gpiochip_generic_request(struct gpio_chip *gc, unsigned int offset) { -#ifdef CONFIG_PINCTRL - if (list_empty(&gc->gpiodev->pin_ranges)) - return 0; -#endif - return pinctrl_gpio_request(gc->gpiodev->base + offset); } EXPORT_SYMBOL_GPL(gpiochip_generic_request); @@ -1717,11 +1712,6 @@ EXPORT_SYMBOL_GPL(gpiochip_generic_request); */ void gpiochip_generic_free(struct gpio_chip *gc, unsigned int offset) { -#ifdef CONFIG_PINCTRL - if (list_empty(&gc->gpiodev->pin_ranges)) - return; -#endif - pinctrl_gpio_free(gc->gpiodev->base + offset); } EXPORT_SYMBOL_GPL(gpiochip_generic_free); -- cgit v1.2.3-70-g09d2 From 660c619b9d7ccd28648ee3766cdbe94ec7b27402 Mon Sep 17 00:00:00 2001 From: Andy Shevchenko Date: Mon, 7 Mar 2022 13:56:23 +0200 Subject: gpiolib: acpi: Convert ACPI value of debounce to microseconds It appears that GPIO ACPI library uses ACPI debounce values directly. However, the GPIO library APIs expect the debounce timeout to be in microseconds. Convert ACPI value of debounce to microseconds. While at it, document this detail where it is appropriate. BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=215664 Reported-by: Kai-Heng Feng Fixes: 8dcb7a15a585 ("gpiolib: acpi: Take into account debounce settings") Signed-off-by: Andy Shevchenko Tested-by: Kai-Heng Feng Reviewed-by: Mika Westerberg Signed-off-by: Bartosz Golaszewski --- drivers/gpio/gpiolib-acpi.c | 6 ++++-- drivers/gpio/gpiolib.c | 10 ++++++++++ 2 files changed, 14 insertions(+), 2 deletions(-) (limited to 'drivers/gpio/gpiolib.c') diff --git a/drivers/gpio/gpiolib-acpi.c b/drivers/gpio/gpiolib-acpi.c index c0f6a25c3279..a5495ad31c9c 100644 --- a/drivers/gpio/gpiolib-acpi.c +++ b/drivers/gpio/gpiolib-acpi.c @@ -307,7 +307,8 @@ static struct gpio_desc *acpi_request_own_gpiod(struct gpio_chip *chip, if (IS_ERR(desc)) return desc; - ret = gpio_set_debounce_timeout(desc, agpio->debounce_timeout); + /* ACPI uses hundredths of milliseconds units */ + ret = gpio_set_debounce_timeout(desc, agpio->debounce_timeout * 10); if (ret) dev_warn(chip->parent, "Failed to set debounce-timeout for pin 0x%04X, err %d\n", @@ -1035,7 +1036,8 @@ int acpi_dev_gpio_irq_get_by(struct acpi_device *adev, const char *name, int ind if (ret < 0) return ret; - ret = gpio_set_debounce_timeout(desc, info.debounce); + /* ACPI uses hundredths of milliseconds units */ + ret = gpio_set_debounce_timeout(desc, info.debounce * 10); if (ret) return ret; diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 005642068c0b..defb7c464b87 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -2217,6 +2217,16 @@ static int gpio_set_bias(struct gpio_desc *desc) return gpio_set_config_with_argument_optional(desc, bias, arg); } +/** + * gpio_set_debounce_timeout() - Set debounce timeout + * @desc: GPIO descriptor to set the debounce timeout + * @debounce: Debounce timeout in microseconds + * + * The function calls the certain GPIO driver to set debounce timeout + * in the hardware. + * + * Returns 0 on success, or negative error code otherwise. + */ int gpio_set_debounce_timeout(struct gpio_desc *desc, unsigned int debounce) { return gpio_set_config_with_argument_optional(desc, -- cgit v1.2.3-70-g09d2