[PATCH 5.8+ regression fix] i2c: core: Restore acpi_walk_dep_device_list() getting called after registering the ACPI i2c devs

[Hans de Goede <hdegoede@redhat.com>]

Commit 21653a4181ff ("i2c: core: Call i2c_acpi_install_space_handler()
before i2c_acpi_register_devices()")'s intention was to only move the
acpi_install_address_space_handler() call to the point before where
the ACPI declared i2c-children of the adapter where instantiated by
i2c_acpi_register_devices().

But i2c_acpi_install_space_handler() had a call to
acpi_walk_dep_device_list() hidden (that is I missed it) at the end
of it, so as an unwanted side-effect now acpi_walk_dep_device_list()
was also being called before i2c_acpi_register_devices().

Move the acpi_walk_dep_device_list() call to the end of
i2c_acpi_register_devices(), so that it is once again called *after*
the i2c_client-s hanging of the adapter have been created.

This fixes the Microsoft Surface Go 2 hanging at boot.

Fixes: 21653a4181ff ("i2c: core: Call i2c_acpi_install_space_handler() before i2c_acpi_register_devices()")
Suggested-by: Maximilian Luz <luzmaximilian@gmail.com>
Reported-and-tested-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
 drivers/i2c/i2c-core-acpi.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/drivers/i2c/i2c-core-acpi.c b/drivers/i2c/i2c-core-acpi.c
index e627d7b2790f..37c510d9347a 100644
--- a/drivers/i2c/i2c-core-acpi.c
+++ b/drivers/i2c/i2c-core-acpi.c
@@ -264,6 +264,7 @@ static acpi_status i2c_acpi_add_device(acpi_handle handle, u32 level,
 void i2c_acpi_register_devices(struct i2c_adapter *adap)
 {
 	acpi_status status;
+	acpi_handle handle;
 
 	if (!has_acpi_companion(&adap->dev))
 		return;
@@ -274,6 +275,15 @@ void i2c_acpi_register_devices(struct i2c_adapter *adap)
 				     adap, NULL);
 	if (ACPI_FAILURE(status))
 		dev_warn(&adap->dev, "failed to enumerate I2C slaves\n");
+
+	if (!adap->dev.parent)
+		return;
+
+	handle = ACPI_HANDLE(adap->dev.parent);
+	if (!handle)
+		return;
+
+	acpi_walk_dep_device_list(handle);
 }
 
 static const struct acpi_device_id i2c_acpi_force_400khz_device_ids[] = {
@@ -719,7 +729,6 @@ int i2c_acpi_install_space_handler(struct i2c_adapter *adapter)
 		return -ENOMEM;
 	}
 
-	acpi_walk_dep_device_list(handle);
 	return 0;
 }
 
-- 
2.28.0