Vincent Whitchurch a47cd740b1 iio: Use per-device lockdep class for mlock ... [ Upstream commit 2bc9cd66eb ] If an IIO driver uses callbacks from another IIO driver and calls iio_channel_start_all_cb() from one of its buffer setup ops, then lockdep complains due to the lock nesting, as in the below example with lmp91000. Since the locks are being taken on different IIO devices, there is no actual deadlock. Fix the warning by telling lockdep to use a different class for each iio_device. ============================================ WARNING: possible recursive locking detected -------------------------------------------- python3/23 is trying to acquire lock: (&indio_dev->mlock){+.+.}-{3:3}, at: iio_update_buffers but task is already holding lock: (&indio_dev->mlock){+.+.}-{3:3}, at: enable_store other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&indio_dev->mlock); lock(&indio_dev->mlock); *** DEADLOCK *** May be due to missing lock nesting notation 5 locks held by python3/23: #0: (sb_writers#5){.+.+}-{0:0}, at: ksys_write #1: (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter #2: (kn->active#14){.+.+}-{0:0}, at: kernfs_fop_write_iter #3: (&indio_dev->mlock){+.+.}-{3:3}, at: enable_store #4: (&iio_dev_opaque->info_exist_lock){+.+.}-{3:3}, at: iio_update_buffers Call Trace: __mutex_lock iio_update_buffers iio_channel_start_all_cb lmp91000_buffer_postenable __iio_update_buffers enable_store Fixes: 67e17300dc ("iio: potentiostat: add LMP91000 support") Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Link: https://lore.kernel.org/r/20220829091840.2791846-1-vincent.whitchurch@axis.com Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Sasha Levin <sashal@kernel.org>		2022-10-21 12:38:43 +02:00
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accel
adc	Char / Misc / Other smaller driver subsystem updates for 5.19-rc1	2022-06-03 11:36:34 -07:00
afe	iio: afe: rescale: add offset support	2022-02-27 13:38:10 +00:00
common	iio: cros: Register FIFO callback after sensor is registered	2022-07-18 18:29:13 +01:00
dac
frequency
gyro
imu	iio: adis: stylistic changes	2022-01-23 18:03:37 +00:00
timer
buffer-dma.h	iio: buffer-dma: Remove unused iio_buffer_block struct	2021-11-27 15:12:01 +00:00
buffer-dmaengine.h
buffer.h	iio: Add output buffer support	2021-10-19 08:30:44 +01:00
buffer_impl.h	iio: Add output buffer support	2021-10-19 08:30:44 +01:00
configfs.h
consumer.h
driver.h	iio: inkern: introduce devm_iio_map_array_register() short-hand function	2021-10-19 08:27:34 +01:00
events.h
hw-consumer.h
iio-opaque.h	iio: Use per-device lockdep class for mlock	2022-10-21 12:38:43 +02:00
iio.h	iio: trigger: move trig->owner init to trigger allocate() stage	2022-07-16 16:24:19 +01:00
kfifo_buf.h	iio: core: Simplify the registration of kfifo buffers	2022-04-10 16:25:46 +01:00
machine.h
sw_device.h
sw_trigger.h
sysfs.h
trigger.h	iio: trigger: move trig->owner init to trigger allocate() stage	2022-07-16 16:24:19 +01:00
trigger_consumer.h
triggered_buffer.h	iio: triggered-buffer: extend support to configure output buffers	2021-10-19 08:30:45 +01:00
triggered_event.h
types.h	iio: core: Introduce IIO_VAL_INT_64.	2021-11-17 17:51:34 +00:00