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

[Wolfram Sang <wsa+renesas@sang-engineering.com>]

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On Fri, May 29, 2026 at 03:38:35PM +0530, 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+.

Shall this go in via i2c?


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