[PATCH 1/1] i2c: core: Call i2c_acpi_install_space_handler() before i2c_acpi_register_devices()

Kai-Heng Feng kai.heng.feng at canonical.com
Tue Sep 22 14:22:56 UTC 2020

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

BugLink: https://bugs.launchpad.net/bugs/1853277

Some ACPI i2c-devices _STA method (which is used to detect if the device
is present) use autodetection code which probes which device is present
over i2c. This requires the I2C ACPI OpRegion handler to be registered
before we enumerate i2c-clients under the i2c-adapter.

This fixes the i2c touchpad on the Lenovo ThinkBook 14-IIL and
ThinkBook 15 IIL not getting an i2c-client instantiated and thus not

BugLink: https://bugzilla.redhat.com/show_bug.cgi?id=1842039
Signed-off-by: Hans de Goede <hdegoede at redhat.com>
Reviewed-by: Mika Westerberg <mika.westerberg at linux.intel.com>
Signed-off-by: Wolfram Sang <wsa at kernel.org>
(cherry picked from commit 21653a4181ff292480599dad996a2b759ccf050f)
Signed-off-by: Kai-Heng Feng <kai.heng.feng at canonical.com>
 drivers/i2c/i2c-core-base.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c
index 4f09d4c31828..7031393c7480 100644
--- a/drivers/i2c/i2c-core-base.c
+++ b/drivers/i2c/i2c-core-base.c
@@ -1336,8 +1336,8 @@ static int i2c_register_adapter(struct i2c_adapter *adap)
 	/* create pre-declared device nodes */
-	i2c_acpi_register_devices(adap);
+	i2c_acpi_register_devices(adap);
 	if (adap->nr < __i2c_first_dynamic_bus_num)

More information about the kernel-team mailing list