Re: [PATCH v8 0/2] i2c: designware: fix WACF2200 touchscreen probe ordering

[Mario Limonciello <superm1@kernel.org>]

On 5/29/26 12:08, Hardik Prakash wrote:
> This series fixes the non-functional WACF2200 touchscreen on Lenovo
> Yoga 7 14AGP11 by:
> 
> 1. Reverting the earlier DMI-specific GPIO IRQ quirk (patch 1 of the
>     original series, already in Torvalds' tree) which is no longer
>     needed.
> 
> 2. Adding a generic probe deferral in i2c-designware that walks ACPI
>     child devices, finds GpioInt resources, and defers probe until the
>     referenced GPIO controllers are fully bound.
> 
> Testing confirms patch 2 alone is sufficient — the existing
> amd_gpio_irq_enable() flow works correctly once probe ordering is
> fixed, making the manual IRQ restoration in the reverted patch
> unnecessary.
> 
> The probe ordering race was confirmed via dynamic debug tracing:
> 
>    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
> 
> Tested on Lenovo Yoga 7 14AGP11 (83TD), Fedora 44, kernel 7.1.0-rc5+.
> 
> v8:
>   - Add revert of now-unnecessary patch 1 (Mario Limonciello)
>   - Collect Acked-by (Bartosz Golaszewski) and Reviewed-by (Mario Limonciello)
> 
> v7:
>   - Fix unused 'ret' variable in check_child_gpioint() (kernel test robot)
>   - Replace BugLink: with Link: (Bartosz Golaszewski)
>   - Add Reported-by and Closes tags for kernel test robot warning
> 
> v6:
>   - Replace DMI-specific deferral with generic GpioInt dependency check
>     walking ACPI child devices (suggested by Mario Limonciello)
> 
> v5:
>   - Add blank line before #include <linux/acpi.h> (Bartosz Golaszewski)
>   - Use scoped_guard(device, gpio_dev) (Bartosz Golaszewski)
> 
> v4:
>   - Rebase onto Linus Walleij's tree
>   - Use --base so series is correctly 1/1 (Andy Shevchenko)
> 
> v3:
>   - Fix variable declaration style (Andy Shevchenko)
>   - Add BugLink tag (Andy Shevchenko)
>   - CC AMD engineers (Andy Shevchenko)
> 
> v2:
>   - Replace custom HID/UID lookup with acpi_dev_get_first_match_dev()
>   - Use device_is_bound() under device_lock() with explanatory comments
>   - 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 (2):
>    Revert "pinctrl-amd: enable IRQ for WACF2200 touchscreen on Lenovo
>      Yoga 7 14AGP11"
>    i2c: designware: defer probe if child GpioInt controllers are not
>      bound
> 
>   drivers/i2c/busses/i2c-designware-platdrv.c | 156 ++++++++++++++++++++
>   drivers/pinctrl/pinctrl-amd.c               |  35 -----
>   2 files changed, 156 insertions(+), 35 deletions(-)
> 
> base-commit: 8fde5d1d47f6

I've left some tags on your series, no need to resend for them though if 
no other feedback.

They should be able to be picked up by the maintainers with b4.