Re: [PATCH v5 0/1] i2c: designware: fix probe ordering for AMD GPIO on Lenovo Yoga 7 14AGP11

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

On 5/19/26 09:39, Bartosz Golaszewski wrote:
> On Tue, May 19, 2026 at 4:28 PM Mario Limonciello
> <mario.limonciello@amd.com> wrote:
>>
>>>
>>> gpiochip_add_data() at 0.285952 makes the GPIO chip visible to the
>>> system before amd_gpio_probe() has finished. AMDI0010:02 starts probing
>>> at 0.301454 while amd_gpio_probe() is still completing. This is why
>>> device_is_bound() works and initcall promotion does not -- it waits for
>>> probe completion, not just gpiochip registration.
>>
>> What is the boot time impact to adding device_is_bound() check?
>>
>> Bartosz, thoughts?
>>
> 
> My thoughts are that ACPI could use some fw_devlink. :) It's not a new
> problem, we've fixed it for OF systems.
> 
> Could we modify gpiolib-acpi.c to return -EPROBE_DEFER if the parent
> device of the GPIO chip is not bound yet instead? When resolving the
> reference to the remote GPIO controller we have an address of the
> struct acpi_device. I suppose there's a platform device that is its
> child and then the logical GPIO controller device, is that correct?
> Can we check if the platform device in question is bound at the
> subsystem level?
> 
> Bart

I like this idea.  I guess something like this:

diff --git a/drivers/gpio/gpiolib-acpi-core.c 
b/drivers/gpio/gpiolib-acpi-core.c
index eb8a40cfb7a98..e3511398b1f84 100644
--- a/drivers/gpio/gpiolib-acpi-core.c
+++ b/drivers/gpio/gpiolib-acpi-core.c
@@ -142,6 +142,13 @@ static struct gpio_desc *acpi_get_gpiod(char *path, 
unsigned int pin)
         if (!gdev)
                 return ERR_PTR(-EPROBE_DEFER);

+       if (gdev->dev.parent) {
+               scoped_guard(device, gdev->dev.parent) {
+                       if (!device_is_bound(gdev->dev.parent))
+                               return ERR_PTR(-EPROBE_DEFER);
+               }
+       }
+
         /*
          * FIXME: keep track of the reference to the GPIO device somehow
          * instead of putting it here.