This is a note to let you know that I've just added the patch titled i2c: core: Restore acpi_walk_dep_device_list() getting called after registering the ACPI i2c devs to the 5.8-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: i2c-core-restore-acpi_walk_dep_device_list-getting-c.patch and it can be found in the queue-5.8 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit e900ed08ccc9816c0f9912ea6b82c7e0807820a6 Author: Hans de Goede <hdegoede@xxxxxxxxxx> Date: Wed Oct 14 16:41:58 2020 +0200 i2c: core: Restore acpi_walk_dep_device_list() getting called after registering the ACPI i2c devs [ Upstream commit 8058d69905058ec8f467a120b5ec5bb831ea67f3 ] 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()") Link: https://bugzilla.kernel.org/show_bug.cgi?id=209627 Reported-by: Rainer Finke <rainer@xxxxxxxx> Reported-by: Kieran Bingham <kieran.bingham@xxxxxxxxxxxxxxxx> Suggested-by: Maximilian Luz <luzmaximilian@xxxxxxxxx> Tested-by: Kieran Bingham <kieran.bingham@xxxxxxxxxxxxxxxx> Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx> Signed-off-by: Wolfram Sang <wsa@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/i2c/i2c-core-acpi.c b/drivers/i2c/i2c-core-acpi.c index 2ade99b105b91..bbf8dd491d245 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); } const struct acpi_device_id * @@ -729,7 +739,6 @@ int i2c_acpi_install_space_handler(struct i2c_adapter *adapter) return -ENOMEM; } - acpi_walk_dep_device_list(handle); return 0; }