[PATCH v3 0/1] i2c: designware: fix probe ordering for AMD GPIO on Lenovo Yoga 7 14AGP11

[PATCH v3 0/1] i2c: designware: fix probe ordering for AMD GPIO on Lenovo Yoga 7 14AGP11

[Hardik Prakash]

The Wacom WACF2200 touchscreen on the Lenovo Yoga 7 14AGP11 (83TD) is
non-functional on Linux due to two bugs. Patch 1 (pinctrl-amd GPIO IRQ
fix) has already been taken into Linus Walleij's tree. This v3 resend
covers patch 2 only, addressing Andy Shevchenko's formatting feedback.

Root cause: i2c_designware probes AMDI0010:02 before pinctrl-amd's
probe completes, so GPIO 157 (WACF2200 GpioInt per ACPI _CRS) has its
interrupt bits cleared when the first I2C transaction is attempted,
causing lost arbitration errors. The udev rebind workaround (which
works because pinctrl-amd has finished by userspace time) confirms
probe ordering as the root cause.

Note: the dual-master hypothesis raised by Mario Limonciello was
investigated. TPNL's _DSM (UUID 3cdff6f7-4267-4555-ad05-b30a3d8938de)
is a pure query method returning a constant HID descriptor address with
no side effects, making firmware acting as secondary I2C master unlikely
on this hardware. Awaiting Mario and Bart's technical verdict before
any further approach changes.

v3:
 - Patch 2 only (patch 1 already in Linus Walleij's tree)
 - Fix variable declaration style in dw_i2c_needs_amd_gpio_dep (Andy Shevchenko)
 - Add BugLink tag (Andy Shevchenko)
 - Add -v3 subject versioning (Andy Shevchenko)
 - CC AMD engineers (Andy Shevchenko)

v2:
 - Replace custom HID/UID lookup with acpi_dev_get_first_match_dev() (Andy Shevchenko)
 - Use acpi_get_first_physical_node() for platform device lookup
 - Use device_is_bound() under device_lock() with explanatory comments
 - Fix dev_warn to use dev_name() instead of hardcoded suffix
 - Fix commit message (removed incorrect "existing" reference)
 - Add Assisted-by tags per coding-assistants.rst

Kernel bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=221494
Related: https://bugzilla.kernel.org/show_bug.cgi?id=221454

Hardik Prakash (1):
  i2c: designware: fix probe ordering for AMD GPIO on Lenovo Yoga 7
    14AGP11

 drivers/i2c/busses/i2c-designware-platdrv.c | 77 +++++++++++++++++++++
 1 file changed, 77 insertions(+)

[PATCH v3 2/2] i2c: designware: fix probe ordering for AMD GPIO on Lenovo Yoga 7 14AGP11

[Hardik Prakash]

On Lenovo Yoga 7 14AGP11 (83TD), the WACF2200 touchscreen fails with
lost arbitration errors on AMDI0010:02 at boot. The root cause is a
probe ordering issue: i2c_designware probes AMDI0010:02 before
pinctrl-amd has finished initialising, so the GPIO 157 interrupt
needed by the touchscreen is not yet enabled.

Add a DMI-matched deferral in dw_i2c_plat_probe() that uses
device_is_bound() under device_lock() to correctly wait until
pinctrl-amd's probe has fully completed. Use acpi_dev_get_first_match_dev()
for robust HID/UID-based GPIO controller lookup instead of string
name matching.

Signed-off-by: Hardik Prakash <hardikprakash.official@gmail.com>
Assisted-by: Claude:claude-sonnet-4-6
Assisted-by: GPT-Codex:gpt-5.2-codex
BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=221494
---
 drivers/i2c/busses/i2c-designware-platdrv.c | 77 +++++++++++++++++++++
 1 file changed, 77 insertions(+)

diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c b/drivers/i2c/busses/i2c-designware-platdrv.c
index 3351c4a9ef118..3ffc3d757fbd1 100644
--- a/drivers/i2c/busses/i2c-designware-platdrv.c
+++ b/drivers/i2c/busses/i2c-designware-platdrv.c
@@ -8,6 +8,7 @@
  * 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>
@@ -86,6 +87,78 @@ static const struct dmi_system_id dw_i2c_hwmon_class_dmi[] = {
 	{ } /* terminate list */
 };
 
+static const struct dmi_system_id dw_i2c_amd_gpio_defer_dmi[] = {
+	{
+		.ident = "Lenovo Yoga 7 14AGP11",
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
+			DMI_MATCH(DMI_PRODUCT_NAME, "83TD"),
+			DMI_MATCH(DMI_BOARD_NAME, "LNVNB161216"),
+		},
+	},
+	{ } /* terminate list */
+};
+
+static bool dw_i2c_needs_amd_gpio_dep(struct device *device)
+{
+	struct acpi_device *adev;
+
+	if (!dmi_check_system(dw_i2c_amd_gpio_defer_dmi))
+		return false;
+
+	adev = ACPI_COMPANION(device);
+	if (!adev)
+		return false;
+
+	return acpi_dev_hid_uid_match(adev, "AMDI0010", "2");
+}
+
+static int dw_i2c_defer_for_amd_gpio(struct device *device)
+{
+	struct acpi_device *gpio_adev;
+	struct device *gpio_dev;
+
+	if (!dw_i2c_needs_amd_gpio_dep(device))
+		return 0;
+
+	/*
+	 * Find the AMD GPIO controller by HID/UID and get its physical
+	 * platform device. We need the platform device (not the ACPI device)
+	 * because that is what gets bound by the amd_gpio driver.
+	 */
+	gpio_adev = acpi_dev_get_first_match_dev("AMDI0030", "0", -1);
+	if (!gpio_adev)
+		return -EPROBE_DEFER;
+
+	gpio_dev = acpi_get_first_physical_node(gpio_adev);
+	acpi_dev_put(gpio_adev);
+	if (!gpio_dev)
+		return -EPROBE_DEFER;
+
+	/*
+	 * Check that amd_gpio probe has fully completed, not just that the
+	 * driver pointer is set. The driver pointer is assigned before probe
+	 * finishes, so checking it would allow i2c_designware to probe before
+	 * the GPIO IRQ quirk in amd_gpio_probe() has run.
+	 */
+	device_lock(gpio_dev);
+	if (!device_is_bound(gpio_dev)) {
+		device_unlock(gpio_dev);
+		return -EPROBE_DEFER;
+	}
+	device_unlock(gpio_dev);
+
+	/*
+	 * Create a device link so the driver core enforces probe/remove
+	 * ordering between this I2C controller and the GPIO controller.
+	 */
+	if (!device_link_add(device, gpio_dev, DL_FLAG_AUTOREMOVE_CONSUMER))
+		dev_warn(device, "failed to add device link to %s\n",
+			 dev_name(gpio_dev));
+
+	return 0;
+}
+
 static const struct i2c_dw_semaphore_callbacks i2c_dw_semaphore_cb_table[] = {
 #ifdef CONFIG_I2C_DESIGNWARE_BAYTRAIL
 	{
@@ -138,6 +211,10 @@ static int dw_i2c_plat_probe(struct platform_device *pdev)
 	struct dw_i2c_dev *dev;
 	int irq, ret;
 
+	ret = dw_i2c_defer_for_amd_gpio(device);
+	if (ret)
+		return ret;
+
 	irq = platform_get_irq_optional(pdev, 0);
 	if (irq == -ENXIO)
 		flags |= ACCESS_POLLING;
-- 
2.54.0

Re: [PATCH v3 0/1] i2c: designware: fix probe ordering for AMD GPIO on Lenovo Yoga 7 14AGP11

[Mario Limonciello]

On 5/15/26 11:15, Hardik Prakash wrote:
> The Wacom WACF2200 touchscreen on the Lenovo Yoga 7 14AGP11 (83TD) is
> non-functional on Linux due to two bugs. Patch 1 (pinctrl-amd GPIO IRQ
> fix) has already been taken into Linus Walleij's tree. This v3 resend
> covers patch 2 only, addressing Andy Shevchenko's formatting feedback.
> 
> Root cause: i2c_designware probes AMDI0010:02 before pinctrl-amd's
> probe completes, so GPIO 157 (WACF2200 GpioInt per ACPI _CRS) has its
> interrupt bits cleared when the first I2C transaction is attempted,
> causing lost arbitration errors. The udev rebind workaround (which
> works because pinctrl-amd has finished by userspace time) confirms
> probe ordering as the root cause.
> 
> Note: the dual-master hypothesis raised by Mario Limonciello was
> investigated. TPNL's _DSM (UUID 3cdff6f7-4267-4555-ad05-b30a3d8938de)
> is a pure query method returning a constant HID descriptor address with
> no side effects, making firmware acting as secondary I2C master unlikely
> on this hardware. Awaiting Mario and Bart's technical verdict before
> any further approach changes.
> 
> v3:
>   - Patch 2 only (patch 1 already in Linus Walleij's tree)
>   - Fix variable declaration style in dw_i2c_needs_amd_gpio_dep (Andy Shevchenko)
>   - Add BugLink tag (Andy Shevchenko)
>   - Add -v3 subject versioning (Andy Shevchenko)
>   - CC AMD engineers (Andy Shevchenko)
> 
> v2:
>   - Replace custom HID/UID lookup with acpi_dev_get_first_match_dev() (Andy Shevchenko)
>   - Use acpi_get_first_physical_node() for platform device lookup
>   - Use device_is_bound() under device_lock() with explanatory comments
>   - Fix dev_warn to use dev_name() instead of hardcoded suffix
>   - Fix commit message (removed incorrect "existing" reference)
>   - Add Assisted-by tags per coding-assistants.rst
> 
> Kernel bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=221494
> Related: https://bugzilla.kernel.org/show_bug.cgi?id=221454
> 
> Hardik Prakash (1):
>    i2c: designware: fix probe ordering for AMD GPIO on Lenovo Yoga 7
>      14AGP11
> 
>   drivers/i2c/busses/i2c-designware-platdrv.c | 77 +++++++++++++++++++++
>   1 file changed, 77 insertions(+)

I have another idea.  Why don't we just move pinctrl-amd to initialize 
earlier?  That should avoid the problem without more quirks I think.

Something like this:

╰─❯ git diff
diff --git a/drivers/pinctrl/pinctrl-amd.c b/drivers/pinctrl/pinctrl-amd.c
index e3128b0045d22..56a189082351b 100644
--- a/drivers/pinctrl/pinctrl-amd.c
+++ b/drivers/pinctrl/pinctrl-amd.c
@@ -1292,7 +1292,18 @@ static struct platform_driver amd_gpio_driver = {
         .remove         = amd_gpio_remove,
  };

-module_platform_driver(amd_gpio_driver);
+static int __init amd_gpio_init(void)
+{
+       return platform_driver_register(&amd_gpio_driver);
+}
+subsys_initcall(amd_gpio_init);
+
+static void __exit amd_gpio_exit(void)
+{
+       platform_driver_unregister(&amd_gpio_driver);
+}
+module_exit(amd_gpio_exit);

  MODULE_AUTHOR("Ken Xue <Ken.Xue@amd.com>, Jeff Wu <Jeff.Wu@amd.com>");
  MODULE_DESCRIPTION("AMD GPIO pinctrl driver");
+MODULE_LICENSE("GPL");