[v4,0/8] Fix up and simplify error recovery mechanism

Message

Can Guo July 20, 2020, 6:35 a.m. UTC

The changes have been tested with error injections of multiple error types (and
all kinds of mixture of them) during runtime, e.g. hibern8 enter/ exit error,
power mode change error and fatal/non-fatal error from IRQ context. During the
test, error injections happen randomly across all contexts, e.g. clk scaling,
clk gate/ungate, runtime suspend/resume and IRQ.

There are a few more fixes to resolve other minor problems based on the main
change, such as LINERESET handling and racing btw error handler and system
suspend/resume/shutdown, but they will be pushed after this series is taken,
due to there are already too many lines in these changes.

Change since v3:
- Split the original change "scsi: ufs: Fix up and simplify error recovery mechanism" into 5 changes

Change since v2:
- Incorporate Bart's comment to change "scsi: ufs: Add checks before setting clk-gating states"
- Revised the commit msg of change "scsi: ufs: Fix up and simplify error recovery mechanism"

Change since v1:
- Fixed a compilation error in case that CONFIG_PM is N


Can Guo (8):
  scsi: ufs: Add checks before setting clk-gating states
  scsi: ufs: Fix imbalanced scsi_block_reqs_cnt caused by ufshcd_hold()
  ufs: ufs-qcom: Fix a few BUGs in func ufs_qcom_dump_dbg_regs()
  scsi: ufs: Add some debug infos to ufshcd_print_host_state
  scsi: ufs: Fix concurrency of error handler and other error recovery
    paths
  scsi: ufs: Recover hba runtime PM error in error handler
  scsi: ufs: Move dumps in IRQ handler to error handler
  scsi: ufs: Fix a racing problem btw error handler and runtime PM ops

 drivers/scsi/ufs/ufs-qcom.c  |  17 +-
 drivers/scsi/ufs/ufs-sysfs.c |   1 +
 drivers/scsi/ufs/ufshcd.c    | 499 +++++++++++++++++++++++++++----------------
 drivers/scsi/ufs/ufshcd.h    |  15 ++
 4 files changed, 333 insertions(+), 199 deletions(-)