+++ /dev/null
-From 0a4bb2abc3e56d7be6e69b050c88ba52c87e22bf Mon Sep 17 00:00:00 2001
-From: Hardik Prakash <hardikprakash.official@gmail.com>
-Date: Sat, 18 Jul 2026 11:13:31 +0530
-Subject: i2c: designware: defer probe if child GpioInt controllers are not bound
-
-From: Hardik Prakash <hardikprakash.official@gmail.com>
-
-commit 0a4bb2abc3e56d7be6e69b050c88ba52c87e22bf upstream.
-
-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 <mario.limonciello@amd.com>
-Suggested-by: Andy Shevchenko <andriy.shevchenko@intel.com>
-Signed-off-by: Hardik Prakash <hardikprakash.official@gmail.com>
-Assisted-by: Claude:claude-sonnet-5
-Assisted-by: DeepSeek:deepseek-v4-pro
-Cc: <stable@vger.kernel.org> # v7.1+
-Acked-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
-Reviewed-by: Andy Shevchenko <andriy.shevchenko@intel.com>
-Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
-Link: https://lore.kernel.org/r/20260718054330.8975-2-hardikprakash.official@gmail.com
-Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
----
- drivers/i2c/busses/i2c-designware-platdrv.c | 80 ++++++++++++++++++++++++++++
- 1 file changed, 80 insertions(+)
-
---- 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 <linux/acpi.h>
- #include <linux/clk-provider.h>
- #include <linux/clk.h>
- #include <linux/delay.h>
- #include <linux/dmi.h>
- #include <linux/err.h>
- #include <linux/errno.h>
-+#include <linux/gpio/driver.h>
- #include <linux/i2c.h>
- #include <linux/interrupt.h>
- #include <linux/io.h>
-@@ -130,6 +132,80 @@ static int i2c_dw_probe_lock_support(str
- 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 plat
- 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;
projects / thirdparty / kernel / stable-queue.git / commitdiff
