[PATCH v6 0/8] Fix up and simplify error recovery mechanism

Can Guo
2020-07-23T11:46:31Z

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 v5:
- Dropped change "scsi: ufs: Fix imbalanced scsi_block_reqs_cnt caused by ufshcd_hold()" as it is not quite related with this series
- Refined func ufshcd_err_handling_prepare in change "scsi: ufs: Recover hba runtime PM error in error handler"

Change since v4:
- Split the original change "ufs: ufs-qcom: Fix a few BUGs in func ufs_qcom_dump_dbg_regs()" to 2 small 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
ufs: ufs-qcom: Fix race conditions caused by func
ufs_qcom_testbus_config
scsi: ufs-qcom: Fix schedule while atomic error in
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 | 20 +-
drivers/scsi/ufs/ufs-sysfs.c | 1 +
drivers/scsi/ufs/ufshcd.c | 494 +++++++++++++++++++++++++++----------------
drivers/scsi/ufs/ufshcd.h | 15 ++
4 files changed, 333 insertions(+), 197 deletions(-)