[PATCH v4 0/2] Fix lockdep warning with nested instances of i2c-mux

From: Peter Rosin
Date: Fri Jul 20 2018 - 04:39:35 EST


Hi!

Ping. This is almost a resend of v3, but I added tested-by tags from
John and unwrapped a line in the commit message, so it's a v4.

How is this going to find its way to Linus? I can move this through
the i2c-mux tree, but I obviously need a tag for patch 1/2 for that...

Cheers,
Peter

Changes since v3 https://lkml.org/lkml/2018/5/24/994
- Added Tested-by tags from John.
- Unwrapped commit message for patch 2/2.

Changes since v2 https://lkml.org/lkml/2018/5/24/176
- EXPORT_SYMBOL_GPL(rt_mutex_lock_nested) is more appropriate (the
rt_ prefix was missing).

Changes since v1 https://lkml.org/lkml/2018/5/24/93
- Further compile tests indicated a missing #define for rt_mutex_lock
with lockdep enabled, so that one is added.
- I have verified that I don't get any lockdep splat for a local i2c-mux
setup with these patches applied, and that I do without them.

Cheers,
Peter

Peter Rosin (2):
rtmutex: allow specifying a subclass for nested locking
i2c: mux: annotate the nested rt_mutex usage

drivers/i2c/i2c-core-base.c | 2 +-
drivers/i2c/i2c-mux.c | 4 ++--
include/linux/rtmutex.h | 7 +++++++
kernel/locking/rtmutex.c | 29 +++++++++++++++++++++++++----
4 files changed, 35 insertions(+), 7 deletions(-)

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2.11.0