9b4e3b804c
commit 59f92868176f191eefde70d284bdfc1ed76a84bc upstream. When reading the voltage: $ cat /sys/bus/iio/devices/iio\:device0/in_voltage0_raw Lockdep complains: [ 153.910616] ====================================================== [ 153.916918] WARNING: possible circular locking dependency detected [ 153.923221] 5.14.0+ #5 Not tainted [ 153.926692] ------------------------------------------------------ [ 153.932992] cat/717 is trying to acquire lock: [ 153.937525] c2585358 (&indio_dev->mlock){+.+.}-{3:3}, at: iio_device_claim_direct_mode+0x28/0x44 [ 153.946541] but task is already holding lock: [ 153.952487] c2585860 (&dln2->mutex){+.+.}-{3:3}, at: dln2_adc_read_raw+0x94/0x2bc [dln2_adc] [ 153.961152] which lock already depends on the new lock. Fix this by not calling into the iio core underneath the dln2->mutex lock. Fixes: 7c0299e879dd ("iio: adc: Add support for DLN2 ADC") Cc: Jack Andersen <jackoalan@gmail.com> Signed-off-by: Noralf Trønnes <noralf@tronnes.org> Link: https://lore.kernel.org/r/20211018113731.25723-1-noralf@tronnes.org Cc: <Stable@vger.kernel.org> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.