Re: i2c designware change broke touchpad of a thinkpad

On 8/10/26 07:23, Hardik Prakash wrote:
> On Sat, 8 Aug 2026, Thorsten Leemhuis wrote:
>> https://www.leemhuis.info/files/misc/dmesg-master-plus_revert
>>
>> [    0.619018] i2c-dw-gpio-dbg: i2c_dw_check_gpio_dependencies(AMDI0010:00)
>> [...]
>> [    1.136010] i2c-dw-gpio-dbg: device_is_bound()=true for AMDI0030:00
> 
> Thanks, this trace looks correct on its face (defer at 0.619s, retry
> succeeds at 1.122-1.136s), but the link above points to the same file
> you sent last round (the master+revert baseline, no debug patch, no
> i2c-dw-gpio-dbg lines in it at all) rather than this new capture.
>> Could you share the full, unfiltered dmesg from this exact boot (the
> one with the debug patch applied)? I need to see where
> "lost arbitration" falls relative to the trace above.

Sorry, picked the wrong file while preparing the mail, it's here:
https://www.leemhuis.info/files/misc/dmesg_patch_dyndbg

Ciao, Thorsten

> Separately, from your DSDT: NFC1 (NXP1001), which shows up as a child
> of AMDI0010:01 in your trace, declares its _CRS as a raw resource
> buffer containing three GPIO resources referencing \_SB.GPIO -- one
> GpioIo and two separate GpioInt entries. Not sure yet if that's
> relevant, but it's a pattern I haven't seen on my hardware
> which I've tested against.
> 
> Thanks,
> Hardik
> 
> On Sun, 9 Aug 2026 at 21:49, Thorsten Leemhuis <[email protected]> wrote:
>>
>> On 8/8/26 22:25, Andy Shevchenko wrote:
>>> On Sat, Aug 08, 2026 at 10:31:28PM +0530, Hardik Prakash wrote:
>>>> On Fri, 7 Aug 2026, Thorsten Leemhuis wrote:
>>>>> This became 0a4bb2abc3e56d ("i2c: designware: defer probe if child
>>>>> GpioInt controllers are not bound") and causes a regression for me: the
>>>>> Touchpad in my ThinkPad T14s Gen 4 (AMD) stopped working. From the
>>>>> kernel log:
>>>>>
>>>>> i2c_designware AMDI0010:01: i2c_dw_handle_tx_abort: lost arbitration
>>>>> i2c_designware AMDI0010:01: controller timed out
>>>>> i2c_hid_acpi i2c-SYNA8018:00: failed to fetch HID descriptor: -110
>>>>> i2c_hid_acpi i2c-SYNA8018:00: Failed to fetch the HID Descriptor
>>>>>
>>>>> Reverting this change in current mainline/master (f9a2394a23482) fixed
>>>>> things for me. Full dmesg of current master and master+revert can be
>>>>> found here:
>>>>>
>>>>> https://www.leemhuis.info/files/misc/dmesg-master
>>>>> https://www.leemhuis.info/files/misc/dmesg-master-plus_revert
>>>> [...]
>>>> Two things that would help narrow this down, whenever you have a moment:
>>
>> Thx for looking into this. Here we go:
>>
>>>> 1. A DSDT dump
>>
>> https://www.leemhuis.info/files/misc/dsdt.dsl
>>
>>>> 2. A dmesg with dynamic debug from a kernel built with the attached
>>>>    patch on top of current mainline/master
>>
>> https://www.leemhuis.info/files/misc/dmesg-master-plus_revert
>>
>> [    0.619018] i2c-dw-gpio-dbg: i2c_dw_check_gpio_dependencies(AMDI0010:00)
>> [    0.619018] i2c-dw-gpio-dbg: check_child_gpioint(adev=XXXX0000:00)
>> [    0.619076] i2c-dw-gpio-dbg: GpioInt resource_source=\_SB.GPIO (len=10)
>> [    0.619079] i2c-dw-gpio-dbg: acpi_fetch_acpi_dev() succeeded,
>> device=AMDI0030:00
>> [    0.619080] i2c-dw-gpio-dbg: gpio_device_find_by_fwnode() returned
>> NULL, deferring
>> [    0.619082] i2c-dw-gpio-dbg: check_child_gpioint ret=-517 (defer)
>> [    0.619102] i2c-dw-gpio-dbg: i2c_dw_check_gpio_dependencies(AMDI0010:01)
>> [    0.619104] i2c-dw-gpio-dbg: check_child_gpioint(adev=SYNA8018:00)
>> [    0.619159] i2c-dw-gpio-dbg: GpioInt resource_source=\_SB.GPIO (len=10)
>> [    0.619162] i2c-dw-gpio-dbg: acpi_fetch_acpi_dev() succeeded,
>> device=AMDI0030:00
>> [    0.619162] i2c-dw-gpio-dbg: gpio_device_find_by_fwnode() returned
>> NULL, deferring
>> [    0.619164] i2c-dw-gpio-dbg: check_child_gpioint ret=-517 (defer)
>> [    1.122517] i2c-dw-gpio-dbg: i2c_dw_check_gpio_dependencies(AMDI0010:00)
>> [    1.122523] i2c-dw-gpio-dbg: check_child_gpioint(adev=XXXX0000:00)
>> [    1.122625] i2c-dw-gpio-dbg: GpioInt resource_source=\_SB.GPIO (len=10)
>> [    1.122636] i2c-dw-gpio-dbg: acpi_fetch_acpi_dev() succeeded,
>> device=AMDI0030:00
>> [    1.122639] i2c-dw-gpio-dbg: gpio_device_find_by_fwnode() succeeded
>> [    1.122642] i2c-dw-gpio-dbg: device_is_bound()=true for AMDI0030:00
>> [    1.135894] i2c-dw-gpio-dbg: i2c_dw_check_gpio_dependencies(AMDI0010:01)
>> [    1.135898] i2c-dw-gpio-dbg: check_child_gpioint(adev=SYNA8018:00)
>> [    1.135976] i2c-dw-gpio-dbg: GpioInt resource_source=\_SB.GPIO (len=10)
>> [    1.135980] i2c-dw-gpio-dbg: acpi_fetch_acpi_dev() succeeded,
>> device=AMDI0030:00
>> [    1.135983] i2c-dw-gpio-dbg: gpio_device_find_by_fwnode() succeeded
>> [    1.135985] i2c-dw-gpio-dbg: device_is_bound()=true for AMDI0030:00
>> [    1.135987] i2c-dw-gpio-dbg: check_child_gpioint(adev=NXP1001:00)
>> [    1.136005] i2c-dw-gpio-dbg: GpioInt resource_source=\_SB.GPIO (len=10)
>> [    1.136008] i2c-dw-gpio-dbg: acpi_fetch_acpi_dev() succeeded,
>> device=AMDI0030:00
>> [    1.136009] i2c-dw-gpio-dbg: gpio_device_find_by_fwnode() succeeded
>> [    1.136010] i2c-dw-gpio-dbg: device_is_bound()=true for AMDI0030:00
>>
>> HTH, Ciao, Thorsten
>>
>>>> On Fri, 7 Aug 2026 at 19:37, Thorsten Leemhuis <[email protected]> wrote:
>>>>> On 7/28/26 10:30, Andi Shyti wrote:
>>>>>> On Sat, Jul 18, 2026 at 11:13:31AM +0530, Hardik Prakash wrote:
>>>>>>> I2C controllers may have child devices with GpioInt resources that
>>>>>>> depend on GPIO controllers being fully initialized. If the I2C
>>>>>>> controller probes and enumerates children before the referenced GPIO
>>>>>>> controller has completed probe, GPIO interrupts may not be properly
>>>>>>> configured, leading to device failures.
>>>>>>>
>>>>>>> On Lenovo Yoga 7 14AGP11, the WACF2200 touchscreen (child of
>>>>>>> AMDI0010:02) has a GpioInt resource pointing to GPIO 157 on the
>>>>>>> pinctrl-amd controller (AMDI0030:00). When i2c-designware probes
>>>>>>> AMDI0010:02 before pinctrl-amd finishes initializing, I2C transactions
>>>>>>> fail with lost arbitration errors:
>>>>>>>
>>>>>>>   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
>>>>>>>
>>>>>>> Add a dependency check that walks ACPI child devices and defers probe
>>>>>>> until any referenced GPIO controller is bound.
>>>
>>> [...]
>>>
>>>>> #regzbot introduced: 0a4bb2abc3e56d
>>>>> #regzbot title i2c: designware: ThinkPad touchpad broke
>>>
>>
>