Re: [PATCH v2 0/2] Fix WACF2200 touchscreen on Lenovo Yoga 7 14AGP11

[Andy Shevchenko <andriy.shevchenko@intel.com>]

On Wed, May 13, 2026 at 11:43:36AM +0530, Hardik Prakash wrote:
> The Wacom WACF2200 touchscreen on the Lenovo Yoga 7 14AGP11 (83TD) is
> completely non-functional on Linux. The I2C bus (AMDI0010:02) fails with
> repeated lost arbitration errors at boot before any driver can probe the
> device. The touchscreen works correctly in UEFI and Windows.
> 
> Investigation using ACPI _CRS decode and Windows/Linux GPIO register
> comparison identified two bugs:
> 
> 1. GPIO 157 (WACF2200 GpioInt per ACPI _CRS) has INTERRUPT_ENABLE and
>    INTERRUPT_MASK cleared by amd_gpio_irq_init() and never restored,
>    preventing the device from signalling the driver. Windows keeps both
>    bits set after initialisation.
> 
> 2. i2c_designware probes AMDI0010:02 before pinctrl-amd's probe
>    completes. A DMI-matched deferral is added to correctly enforce
>    ordering using device_is_bound() under device_lock().
> 
> Patch 1 adds a DMI quirk in pinctrl-amd to restore GPIO 157 interrupt
> bits after amd_gpio_irq_init().
> 
> Patch 2 adds a probe deferral in i2c-designware-platdrv that correctly
> waits for pinctrl-amd to fully complete before AMDI0010:02 is probed,
> using acpi_dev_get_first_match_dev() and acpi_get_first_physical_node()
> for robust device lookup.
> 
> Both patches tested on Lenovo Yoga 7 14AGP11 (83TD), Fedora 44, kernel
> 7.1.0-rc2+. Touch and stylus fully functional across 4 stable reboots.

The Subject in the patches misses versioning, use

	git format-patch -v<N> --cover-letter ...

where <N> is the version, to get proper format in the Subject.

Also link to the bugzilla makes sense as BugLink tag in the patch(es):

BugLink: $URL

Or simple Link.

-- 
With Best Regards,
Andy Shevchenko