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

[Mario Limonciello <mario.limonciello@amd.com>]

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");