I noticed on Nexus 7 that after rebooting from downstream kernel to upstream, the GPIO interrupt is triggering non-stop despite interrupts being disabled for all of GPIOs. This happens because Nexus 7 uses a soft-reboot, meaning that bootloader should take care of resetting hardware, but the bootloader doesn't do it well. As a result, GPIO interrupt may be left ON at a boot time. Let's mask all GPIO interrupts at the driver's initialization time in order to resolve the issue.
Reviewed-by: Andy Shevchenko <[email protected]> Acked-by: Laxman Dewangan <[email protected]> Signed-off-by: Dmitry Osipenko <[email protected]> --- drivers/gpio/gpio-max77620.c | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) diff --git a/drivers/gpio/gpio-max77620.c b/drivers/gpio/gpio-max77620.c index 6c516aa7732d..e090979659eb 100644 --- a/drivers/gpio/gpio-max77620.c +++ b/drivers/gpio/gpio-max77620.c @@ -260,6 +260,30 @@ static int max77620_gpio_set_config(struct gpio_chip *gc, unsigned int offset, return -ENOTSUPP; } +static int max77620_gpio_irq_init_hw(struct gpio_chip *gc) +{ + struct max77620_gpio *gpio = gpiochip_get_data(gc); + unsigned int i; + int err; + + /* + * GPIO interrupts may be left ON after bootloader, hence let's + * pre-initialize hardware to the expected state by disabling all + * the interrupts. + */ + for (i = 0; i < MAX77620_GPIO_NR; i++) { + err = regmap_update_bits(gpio->rmap, GPIO_REG_ADDR(i), + MAX77620_CNFG_GPIO_INT_MASK, 0); + if (err < 0) { + dev_err(gpio->dev, + "failed to disable interrupt: %d\n", err); + return err; + } + } + + return 0; +} + static int max77620_gpio_probe(struct platform_device *pdev) { struct max77620_chip *chip = dev_get_drvdata(pdev->dev.parent); @@ -295,6 +319,7 @@ static int max77620_gpio_probe(struct platform_device *pdev) mgpio->gpio_chip.irq.chip = &max77620_gpio_irqchip; mgpio->gpio_chip.irq.default_type = IRQ_TYPE_NONE; mgpio->gpio_chip.irq.handler = handle_edge_irq; + mgpio->gpio_chip.irq.init_hw = max77620_gpio_irq_init_hw, mgpio->gpio_chip.irq.threaded = true; platform_set_drvdata(pdev, mgpio); -- 2.26.0
