[PATCH v12 0/2] IB/mlx5: Fix loopback rollback and threshold accounting

[Prathamesh Deshpande <prathameshdeshpande7@gmail.com>]

This series fixes transport-domain rollback and inconsistent accounting
in the regular (non-MP) device paths.

Patch 1 fixes TD rollback on mlx5_ib_enable_lb() failure, makes the
success return path explicit, initializes lb.mutex earlier, and destroys
it on cleanup/failure paths.

Patch 2 corrects the loopback threshold logic to use a capability-aware
baseline rather than a hardcoded value and ensures that
user_td/qps counters are rolled back if the hardware command fails.

v12:
- Add mutex_destroy() for lb.mutex in mlx5_ib_stage_init_cleanup() and
  mlx5_ib_stage_init_init() failure paths.
- Keep MP helper behavior unchanged.

v11:
- Dropped the MP locking changes per review feedback
  to keep the logic unchanged.
- Narrowed the scope of Patch 2/2 to focus solely on regular-path
  threshold and accounting fixes.

v10:
- Initialize lb.mutex before multiport master init to avoid race.
- Use <= td_base in disable paths to handle idle/no-TD cases.

v9:
- Address race/state issues around force_enable and enabled.
- Fix TD leak on failure after successful allocation.
- Implement hardware-aware thresholds via mlx5_ib_lb_td_base() to
  handle both TD-capable and no-TD hardware correctly.
- Serialize MP force-enable transitions under lb.mutex.

v8:
- Resubmitted as a fresh, independent thread per maintainer request.
- No functional changes since v7.

v7:
- Split the series into two patches to isolate the return-value/mutex 
  initialization fix from the refcounting logic.
- Moved force_enable check after increments/decrements to fix leaks.
- Updated hardware disable condition to a strict zero-check.

v1-v6:
- Initial combined versions.
- Added deallocation of tdn on failure.
- Moved mutex_init to stage_init_init to prevent crashes on non-ETH.
- Implemented atomic rollback in enable/disable paths.

Prathamesh Deshpande (2):
  IB/mlx5: Fix transport-domain rollback and initialize lb mutex earlier
  IB/mlx5: Fix loopback threshold/accounting in regular path

 drivers/infiniband/hw/mlx5/main.c | 47 ++++++++++++++++++++++---------
 1 file changed, 33 insertions(+), 14 deletions(-)

-- 
2.43.0