From: Hardik Prakash Date: Sat, 18 Jul 2026 05:43:31 +0000 (+0530) Subject: i2c: designware: defer probe if child GpioInt controllers are not bound X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=0a4bb2abc3e56d7be6e69b050c88ba52c87e22bf;p=thirdparty%2Flinux.git i2c: designware: defer probe if child GpioInt controllers are not bound I2C controllers may have child devices with GpioInt resources that depend on GPIO controllers being fully initialized. If the I2C controller probes and enumerates children before the referenced GPIO controller has completed probe, GPIO interrupts may not be properly configured, leading to device failures. On Lenovo Yoga 7 14AGP11, the WACF2200 touchscreen (child of AMDI0010:02) has a GpioInt resource pointing to GPIO 157 on the pinctrl-amd controller (AMDI0030:00). When i2c-designware probes AMDI0010:02 before pinctrl-amd finishes initializing, I2C transactions fail with lost arbitration errors: 0.285952 amd_gpio_probe: registering gpiochip <- GPIO chip visible 0.287121 amd_gpio_probe: requesting parent IRQ <- probe still running 0.301454 AMDI0010:02 dw_i2c_plat_probe: start <- races here 2.348157 lost arbitration Add a dependency check that walks ACPI child devices and defers probe until any referenced GPIO controller is bound. Fixes: 3812a9e84265 ("pinctrl-amd: enable IRQ for WACF2200 touchscreen on Lenovo Yoga 7 14AGP11") Closes: https://bugzilla.kernel.org/show_bug.cgi?id=221494 Suggested-by: Mario Limonciello Suggested-by: Andy Shevchenko Signed-off-by: Hardik Prakash Assisted-by: Claude:claude-sonnet-5 Assisted-by: DeepSeek:deepseek-v4-pro Cc: # v7.1+ Acked-by: Bartosz Golaszewski Reviewed-by: Andy Shevchenko Signed-off-by: Andi Shyti Link: https://lore.kernel.org/r/20260718054330.8975-2-hardikprakash.official@gmail.com --- diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c b/drivers/i2c/busses/i2c-designware-platdrv.c index 6d6e81242f74..c8a203fff4d1 100644 --- a/drivers/i2c/busses/i2c-designware-platdrv.c +++ b/drivers/i2c/busses/i2c-designware-platdrv.c @@ -8,12 +8,14 @@ * Copyright (C) 2007 MontaVista Software Inc. * Copyright (C) 2009 Provigent Ltd. */ +#include #include #include #include #include #include #include +#include #include #include #include @@ -130,6 +132,80 @@ static int i2c_dw_probe_lock_support(struct dw_i2c_dev *dev) return 0; } +#if defined(CONFIG_ACPI) && defined(CONFIG_GPIOLIB) +/* + * Check whether an ACPI GpioInt resource's referenced GPIO controller + * has finished probing. Resources with no named controller (resource + * source string) are skipped, since they can't be resolved to a + * struct device. + */ +static int check_gpioint_resource(struct acpi_resource *ares, void *data) +{ + struct acpi_resource_gpio *agpio; + struct acpi_device *gpio_adev; + struct device *gpio_dev; + acpi_handle handle; + acpi_status status; + + if (!acpi_gpio_get_irq_resource(ares, &agpio)) + return 1; /* not a GpioInt resource, skip */ + + if (!agpio->resource_source.string_length) + return 1; /* no named controller, skip */ + + status = acpi_get_handle(NULL, agpio->resource_source.string_ptr, &handle); + if (ACPI_FAILURE(status)) + return 1; + + gpio_adev = acpi_fetch_acpi_dev(handle); + if (!gpio_adev) + return 1; + + struct gpio_device *gdev __free(gpio_device_put) = + gpio_device_find_by_fwnode(acpi_fwnode_handle(gpio_adev)); + if (!gdev) + return -EPROBE_DEFER; /* controller not registered yet: abort walk */ + + gpio_dev = gpio_device_to_device(gdev)->parent; + + guard(device)(gpio_dev); + if (!device_is_bound(gpio_dev)) + return -EPROBE_DEFER; /* controller not bound yet: abort walk */ + + return 1; /* bound, skip adding to resource list, continue walk */ +} + +static int check_child_gpioint(struct acpi_device *adev, void *data) +{ + LIST_HEAD(res_list); + int ret; + + ret = acpi_dev_get_resources(adev, &res_list, check_gpioint_resource, NULL); + if (ret < 0) + return ret; + + acpi_dev_free_resource_list(&res_list); + + return 0; +} + +static int i2c_dw_check_gpio_dependencies(struct device *dev) +{ + struct acpi_device *adev; + + adev = ACPI_COMPANION(dev); + if (!adev) + return 0; + + return acpi_dev_for_each_child(adev, check_child_gpioint, NULL); +} +#else +static int i2c_dw_check_gpio_dependencies(struct device *dev) +{ + return 0; +} +#endif /* CONFIG_ACPI && CONFIG_GPIOLIB */ + static int dw_i2c_plat_probe(struct platform_device *pdev) { u32 flags = (uintptr_t)device_get_match_data(&pdev->dev); @@ -138,6 +214,10 @@ static int dw_i2c_plat_probe(struct platform_device *pdev) struct dw_i2c_dev *dev; int irq, ret; + ret = i2c_dw_check_gpio_dependencies(device); + if (ret) + return ret; + irq = platform_get_irq_optional(pdev, 0); if (irq == -ENXIO) flags |= ACCESS_POLLING;