iio: accel: bmc150: Don't make the remove function of the second accelerometer unregi...
authorHans de Goede <hdegoede@redhat.com>
Sun, 23 May 2021 17:00:56 +0000 (19:00 +0200)
committerJonathan Cameron <Jonathan.Cameron@huawei.com>
Wed, 9 Jun 2021 19:47:37 +0000 (20:47 +0100)
commitf407e2dca0f559621114eeaf657880d83f237fbd
treeb7c7531a23a8ad3cdcace77f646eb1a21f703d5b
parentf2bf22dc9ea8ead180fc0221874bd556bf1d2685
iio: accel: bmc150: Don't make the remove function of the second accelerometer unregister itself

On machines with dual accelerometers described in a single ACPI fwnode,
the bmc150_accel_probe() instantiates a second i2c-client for the second
accelerometer.

A pointer to this manually instantiated second i2c-client is stored
inside the iio_dev's private-data through bmc150_set_second_device(),
so that the i2c-client can be unregistered from bmc150_accel_remove().

Before this commit bmc150_set_second_device() took only 1 argument so it
would store the pointer in private-data of the iio_dev belonging to the
manually instantiated i2c-client, leading to the bmc150_accel_remove()
call for the second_dev trying to unregister *itself* while it was
being removed, leading to a deadlock and rmmod hanging.

Change bmc150_set_second_device() to take 2 arguments: 1. The i2c-client
which is instantiating the second i2c-client for the 2nd accelerometer and
2. The second-device pointer itself (which also is an i2c-client).

This will store the second_device pointer in the private data of the
iio_dev belonging to the (ACPI instantiated) i2c-client for the first
accelerometer and will make bmc150_accel_remove() unregister the
second_device i2c-client when called for the first client,
avoiding the deadlock.

Fixes: 5bfb3a4bd8f6 ("iio: accel: bmc150: Check for a second ACPI device for BOSC0200")
Cc: Jeremy Cline <jeremy@jcline.org>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
drivers/iio/accel/bmc150-accel-core.c
drivers/iio/accel/bmc150-accel-i2c.c
drivers/iio/accel/bmc150-accel.h