[PATCH 4.14 135/191] i2c: core: Restore acpi_walk_dep_device_list() getting called after registering the ACPI i2c devs

Greg Kroah-Hartman
2020-10-27T14:18:54Z

From: Hans de Goede <hdegoede@redhat.com>

[ 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@finke.cc>
Reported-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Suggested-by: Maximilian Luz <luzmaximilian@gmail.com>
Tested-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
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 0d4d5dcf94f39..52ae674ebf5bf 100644
--- a/drivers/i2c/i2c-core-acpi.c
+++ b/drivers/i2c/i2c-core-acpi.c
@@ -219,6 +219,7 @@ 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;
@@ -229,6 +230,15 @@ 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 *
@@ -684,7 +694,6 @@ int i2c_acpi_install_space_handler(struct i2c_adapter *adapter)
return -ENOMEM;
}

- acpi_walk_dep_device_list(handle);
return 0;
}

--
2.25.1