Re: [PATCH V4 00/17] i3c: mipi-i3c-hci: DMA abort, recovery and related improvements

On 15/05/2026 19:26, Adrian Hunter wrote:
> Hi
> 
> This series improves the robustness of the MIPI I3C HCI DMA mode driver,
> addressing issues observed during error handling and recovery.

Any comments on V4?

> 
> 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 9-11 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 12 factors out a reset-and-restore helper from the suspend path
> for reuse.
> 
> Patch 13 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 14 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 15 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 16-17 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 V4:
> 
>   i3c: mipi-i3c-hci: Add DMA ring abort/reset quirk for Intel controllers
>         Inline HCI_QUIRK_DMA_ABORT_REQUIRES_PIO_RESET check at call site
>         instead of using a helper function
> 
>   i3c: mipi-i3c-hci: Factor out hci_dma_abort()
>         New patch
> 
>   i3c: mipi-i3c-hci: Add DMA ring abort quirk for Intel controllers
>         Factor out hci_dma_abort() into a preceding patch
>         Make hci_dma_requires_hc_abort_quirk() void; move quirk check to caller
> 
>   i3c: mipi-i3c-hci: Base timeouts on actual transfer start time
>         Rename start_time to start_jiffies
> 
>   i3c: mipi-i3c-hci: Consolidate DMA ring allocation
>         Cache allocation size in xfer_alloc_sz to avoid recomputing in
>         hci_dma_free()
> 
> 
> Changes in V3:
> 
>   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
> 	Add Frank's rev'd-by
> 
>   i3c: mipi-i3c-hci: Add DMA-mode recovery for internal controller errors
> 	When erroring out transfers, ensure the final transfer of a
> 	transfer list is processed last
> 
> 
> 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 (17):
>       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: Factor out hci_dma_abort()
>       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  | 333 +++++++++++++++++++++++++--------
>  drivers/i3c/master/mipi-i3c-hci/hci.h  |  22 +++
>  drivers/i3c/master/mipi-i3c-hci/pio.c  |   1 +
>  5 files changed, 354 insertions(+), 90 deletions(-)
> 
> 
> Regards
> Adrian


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