[PATCH V7 0/3] Minor fixes to UFS error handling

[Can Guo <cang@codeaurora.org>]

This series mainly fixes below two things which come along with UFS error
handling in some corner cases.
[1] Concurrency problems btw err_handler and paths like system suspend/resume/shutdown and async scan.
[2] Race condition btw UFS error recovery and task abort which happens to W-LU during suspend/resume/shutdown.

The 1st change is tested with error/fault injections to power mode change
operations during system PM operations and async scan. The 2nd change is
tested by mimicing SSU cmd timeout during suspend/resume/shutdown. The 3rd
one is just a minor change to a check condition in IRQ handler such that
the driver can dump host regs when AH8 error happens.

Change since v6:
- Updated the check condition of updating clk_scaling.active_reqs in __ufshcd_transfer_req_compl()

Change since v5:
- Incorporated Stanley's comment

Change since v4:
- Fixed a typo found by Stanley.

Change since v3:
- Slightly updated some commit msg lines, no code changes.

Change since v2:
- Added one more minor change into this series.

Change since v1:
- Removed Change-Id from commit msg


Can Guo (3):
  scsi: ufs: Serialize eh_work with system PM events and async scan
  scsi: ufs: Fix a race condition between ufshcd_abort and eh_work
  scsi: ufs: Print host regs in IRQ handler when AH8 error happens

 drivers/scsi/ufs/ufshcd.c | 127 ++++++++++++++++++++++++++++++++--------------
 drivers/scsi/ufs/ufshcd.h |   3 ++
 2 files changed, 92 insertions(+), 38 deletions(-)

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