[PATCH v2 0/5] scsi: ufs: Fix device management timeouts and runtime PM errors

[Stanley Jhu]

This series fixes two problems in UFS core entry points that issue
device management commands or touch host registers.

Patch 1/5 restores the millisecond to jiffies conversion of device
management command timeouts. Since the timeout moved to rq->timeout,
a 1500 ms query timeout waits 6 s with CONFIG_HZ=250.

Patches 2/5 to 5/5 handle runtime PM resume errors. Several UFS core,
sysfs, BSG, hwmon, and debugfs entry points call ufshcd_rpm_get_sync()
before accessing host registers or issuing device management and UIC
commands, but ignore its return value.

ufshcd_rpm_get_sync() wraps pm_runtime_get_sync() on the UFS device
W-LUN and returns a negative errno when runtime resume of the W-LUN or
host controller fails, leaving the device or controller in
RPM_SUSPENDED.

Continuing after such a failure can access host registers or issue
commands while the device or controller is not known to be active,
while checking pm_runtime_get_sync() directly would leave
power.usage_count elevated unless balanced with
pm_runtime_put_noidle().

Add ufshcd_rpm_resume_and_get() around pm_runtime_resume_and_get() and
convert the 20 external and helper call sites to abort and propagate the
error when resuming the W-LUN fails. The three lifecycle call sites in
ufshcd_rpm_dev_flush_recheck_work(), ufshcd_wl_shutdown(), and
ufshcd_remove(), plus ufshcd_err_handling_prepare(), are intentionally
left unchanged.

Tested on QEMU ARM64 UFS (SDB and MCQ) with W-LUN runtime resume and
suspend failures via sysfs offline (no behavior change on suspend
failure) and GDB power.disable_depth=1 to make ufshcd_rpm_get_sync()
fail, and on SDB with a timed out query request.

Changes since v1:
- Drop the incorrect claim that a failed W-LUN runtime suspend
  latches power.runtime_error from the cover letter and commit
  messages. The PM core latches a runtime suspend error only if it
  is neither -EBUSY nor -EAGAIN, and in-tree UFS drivers fail W-LUN
  runtime suspend only with -EBUSY or -EAGAIN (Bart).
- Say in the cover letter how the series was tested.
- Describe each failing sequence in patches 2-5 step by step in
  time order, and drop the runtime PM disabled (-EACCES) scenario.

Link: https://lore.kernel.org/linux-scsi/20261025013446.345974-1-stanleyjhu@xxxxxxxxxx/

Stanley Jhu (5):
  scsi: ufs: core: Restore jiffies conversion of device management
    timeouts
  scsi: ufs: core: Introduce ufshcd_rpm_resume_and_get() helper
  scsi: ufs: sysfs: Propagate runtime PM resume errors
  scsi: ufs: bsg: Abort ufs_bsg_request() when runtime resume fails
  scsi: ufs: hwmon, debugfs: Propagate runtime PM resume errors

 drivers/ufs/core/ufs-debugfs.c |  8 +++-
 drivers/ufs/core/ufs-hwmon.c   | 12 +++++-
 drivers/ufs/core/ufs-sysfs.c   | 67 +++++++++++++++++++++++++++-------
 drivers/ufs/core/ufs_bsg.c     |  4 +-
 drivers/ufs/core/ufshcd-priv.h |  5 +++
 drivers/ufs/core/ufshcd.c      |  9 +++--
 6 files changed, 84 insertions(+), 21 deletions(-)


base-commit: 503e6172fa74da6b4944ece458f5534681e51d21
-- 
2.56.0.307.g5fe7bd680c-goog