[PATCH V2 00/16] i3c: mipi-i3c-hci: DMA abort, recovery and related improvements

[Adrian Hunter <adrian.hunter@intel.com>]

Hi

This series improves the robustness of the MIPI I3C HCI DMA mode driver,
addressing issues observed during error handling and recovery.

Patch 1 ensures suspend always invokes io->suspend.

Patches 2-4 fix issues in the existing DMA abort path: preserving the RUN
bit during abort per the MIPI specification, blocking enqueue during
abort/error, and waiting for ring restart completion.

Patches 5-8 improve how partially completed transfer lists are handled
during dequeue: moving hci_dma_xfer_done() earlier so completed
responses are processed before NoOp replacement, completing transfer
lists immediately on error rather than deferring, and detecting when an
abort races with transfer completion to avoid restarting the wrong
transfer list.

Patches 9-10 add Intel-specific quirks for DMA ring abort: a PIO queue
reset after abort, and an HC_CONTROL ABORT before the ring-level abort.

Patch 11 factors out a reset-and-restore helper from the suspend path
for reuse.

Patch 12 adds a full DMA recovery path for internal controller errors.
When the hardware reports a TID mismatch or the ring becomes stuck, the
driver now resets and restores the controller, terminating all in-flight
transfers with an error status.

Patch 13 makes NoOp command handling observable: instead of discarding
NoOp responses, the driver now waits for them to complete and triggers
recovery if they fail.

Patch 14 adjusts transfer timeout accounting to start from when a
transfer actually begins execution rather than when it was queued,
preventing premature timeouts behind slow predecessors.

Patches 15-16 are minor optimizations: consolidating the DMA command and
response ring into a single coherent allocation, and increasing the ring
size to the maximum 255 entries to avoid ring-space exhaustion.


Changes in V2:

  i3c: mipi-i3c-hci: Fix suspend behavior when bus disable falls back to software reset
	Always return 0 from suspend callback
	Amend commit message

  i3c: mipi-i3c-hci: Preserve RUN bit when aborting DMA ring
	Improve commit message

  i3c: mipi-i3c-hci: Prevent DMA enqueue while ring is aborting or in error
	Improve commit message

  i3c: mipi-i3c-hci: Wait for DMA ring restart to complete
	None

  i3c: mipi-i3c-hci: Move hci_dma_xfer_done() definition
	Add Frank's Rev'd-by

  i3c: mipi-i3c-hci: Call hci_dma_xfer_done() from dequeue path
	Add Frank's Rev'd-by

  i3c: mipi-i3c-hci: Complete transfer lists immediately on error
	Rename completing_xfer to final_xfer

  i3c: mipi-i3c-hci: Avoid restarting DMA ring after aborting wrong transfer
	Rename completing_xfer to final_xfer

  i3c: mipi-i3c-hci: Add DMA ring abort/reset quirk for Intel controllers
	None

  i3c: mipi-i3c-hci: Add DMA ring abort quirk for Intel controllers
	None

  i3c: mipi-i3c-hci: Factor out reset-and-restore helper
	Drop redundant i3c_hci_sync_irq_inactive(hci)
	from i3c_hci_reset_and_restore() because it is called by
	hci->io->suspend() anyway

  i3c: mipi-i3c-hci: Add DMA-mode recovery for internal controller errors
	Rename completing_xfer to final_xfer
	Add hci_dma_xfer_done() before checking for an already complete
	transfer
	Improve commit message

  i3c: mipi-i3c-hci: Wait for NoOp commands to complete
	Rename completing_xfer to final_xfer
	Add missing reinit_completion()

  i3c: mipi-i3c-hci: Base timeouts on actual transfer start time
	Do not flag the next transfer as started when there is an error
	which halts the controller
	Instead flag it started at the end of hci_dma_dequeue_xfer()
	Use hci_start_xfer() in pio.c

  i3c: mipi-i3c-hci: Consolidate DMA ring allocation
	Check for failed allocation before assignments to avoid doing
	arithmetic with NULL pointers

  i3c: mipi-i3c-hci: Increase DMA transfer ring size to maximum
	None


Adrian Hunter (16):
  i3c: mipi-i3c-hci: Fix suspend behavior when bus disable falls back to software reset
  i3c: mipi-i3c-hci: Preserve RUN bit when aborting DMA ring
  i3c: mipi-i3c-hci: Prevent DMA enqueue while ring is aborting or in error
  i3c: mipi-i3c-hci: Wait for DMA ring restart to complete
  i3c: mipi-i3c-hci: Move hci_dma_xfer_done() definition
  i3c: mipi-i3c-hci: Call hci_dma_xfer_done() from dequeue path
  i3c: mipi-i3c-hci: Complete transfer lists immediately on error
  i3c: mipi-i3c-hci: Avoid restarting DMA ring after aborting wrong transfer
  i3c: mipi-i3c-hci: Add DMA ring abort/reset quirk for Intel controllers
  i3c: mipi-i3c-hci: Add DMA ring abort quirk for Intel controllers
  i3c: mipi-i3c-hci: Factor out reset-and-restore helper
  i3c: mipi-i3c-hci: Add DMA-mode recovery for internal controller errors
  i3c: mipi-i3c-hci: Wait for NoOp commands to complete
  i3c: mipi-i3c-hci: Base timeouts on actual transfer start time
  i3c: mipi-i3c-hci: Consolidate DMA ring allocation
  i3c: mipi-i3c-hci: Increase DMA transfer ring size to maximum

 drivers/i3c/master/mipi-i3c-hci/cmd.h  |   6 +
 drivers/i3c/master/mipi-i3c-hci/core.c |  82 ++++++--
 drivers/i3c/master/mipi-i3c-hci/dma.c  | 342 +++++++++++++++++++++++++--------
 drivers/i3c/master/mipi-i3c-hci/hci.h  |  22 +++
 drivers/i3c/master/mipi-i3c-hci/pio.c  |   1 +
 5 files changed, 363 insertions(+), 90 deletions(-)


Regards
Adrian

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