[PATCH v5 0/2] Fix lockdep issues seen in CoreSight configfs interface

[Mike Leach]

Issues with lockdep possible deadlock scenarios have been reported when using the
coresight configfs interface handling complex configuration, when unloading modules.

These are due to holding the main configuration mutex during configfs register, but
taking it later when accessing configfs files.

The patches improve the clean up of configurations and update load and unload of
configurations and initialisation of configfs to fix the locking mechanisms.

Applies to coresight/next (5.19-rc2)
Tested on DB410c (with patch [0] also applied to fix separate console boot issue). 

Fixes: eb2ec49606c2 ("coresight: syscfg: Update load API for config loadable modules")
Reported-by: Suzuki Poulose <suzuki.poulose at arm.com>
Signed-off-by: Mike Leach <mike.leach at linaro.org>

[0] https://lkml.kernel.org/r/20220614124618.2830569-1-suzuki.poulose@arm.com

Changes since v4:
No functional change - fixed comment in patch header 1/2 and error string format to
remove checkpatch warning as requested by Mathieu.

Changes since v3:
Addressed minor issues raised by Suzuki.

Changes since v2:
Added additional work to fix load and unload ops after issue recurred
due to file access.

Mike Leach (2):
  coresight: configfs: Fix unload of configurations on module exit
  coresight: syscfg: Update load and unload operations

 .../hwtracing/coresight/coresight-config.h    |   2 +
 .../hwtracing/coresight/coresight-syscfg.c    | 298 +++++++++++++++---
 .../hwtracing/coresight/coresight-syscfg.h    |  13 +
 3 files changed, 261 insertions(+), 52 deletions(-)

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2.17.1