[PATCH v2 0/2] ufs: fix POST_CHANGE pairing and AHIT race condition

[peter.wang at mediatek.com]

From: Peter Wang <peter.wang at mediatek.com>

Patch 1 fixes a bug where POST_CHANGE was skipped on a failed gear
switch, leaving the host in an inconsistent state if resources acquired
in PRE_CHANGE were never released.

Patch 2 fixes a race between the sysfs AHIT update path and the
MediaTek host driver's power mode change path. A mutex and depth
counter are introduced to serialize AHIT register access and ensure
AHIT is correctly restored after the last disabler completes.

The two patches are related: patch 1 guarantees POST_CHANGE is always
called, ensuring the depth counter introduced in patch 2 is always
properly decremented.

Peter Wang (2):
  ufs: always notify POST_CHANGE even on gear switch failure
  ufs: serialize AHIT register access between sysfs and host driver

 drivers/ufs/core/ufshcd.c       | 22 +++++++++++++++++++---
 drivers/ufs/host/ufs-exynos.c   |  4 +++-
 drivers/ufs/host/ufs-mediatek.c | 16 ++++++++++++----
 drivers/ufs/host/ufshcd-pci.c   |  3 ++-
 include/ufs/ufshcd.h            |  8 ++++++++
 5 files changed, 44 insertions(+), 9 deletions(-)

-- 
2.45.2