Re: [PATCH V3 09/16] i3c: mipi-i3c-hci: Add DMA ring abort/reset quirk for Intel controllers

On Mon, May 04, 2026 at 02:33:45PM +0300, Adrian Hunter wrote:
> Some Intel I3C HCI controllers cannot reliably restart a DMA ring after an
> ABORT.  Additional queue resets are required to recover, and must be
> performed using PIO reset bits even while operating in DMA mode.
>
> This behavior is non-standard.  Introduce a controller quirk to opt into
> the required PIO queue resets after a DMA ring abort, and enable it for
> Intel LPSS I3C controllers.
>
> Signed-off-by: Adrian Hunter <[email protected]>
> ---
>
>
> Changes in V2 and V3:
>
> 	None
>
>
>  drivers/i3c/master/mipi-i3c-hci/core.c | 15 ++++++++++++++-
>  drivers/i3c/master/mipi-i3c-hci/dma.c  |  9 +++++++++
>  drivers/i3c/master/mipi-i3c-hci/hci.h  |  2 ++
>  3 files changed, 25 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/i3c/master/mipi-i3c-hci/core.c b/drivers/i3c/master/mipi-i3c-hci/core.c
> index 44617eb3a3f1..770235ad6b25 100644
> --- a/drivers/i3c/master/mipi-i3c-hci/core.c
> +++ b/drivers/i3c/master/mipi-i3c-hci/core.c
> @@ -240,6 +240,18 @@ void mipi_i3c_hci_pio_reset(struct i3c_hci *hci)
>  	reg_write(RESET_CONTROL, RX_FIFO_RST | TX_FIFO_RST | RESP_QUEUE_RST);
>  }
>
> +#define ALL_QUEUES_RST (CMD_QUEUE_RST | RESP_QUEUE_RST | RX_FIFO_RST | TX_FIFO_RST | IBI_QUEUE_RST)
> +
> +void mipi_i3c_hci_pio_reset_all_queues(struct i3c_hci *hci)
> +{
> +	u32 regval;
> +
> +	reg_write(RESET_CONTROL, ALL_QUEUES_RST);
> +	if (readx_poll_timeout_atomic(reg_read, RESET_CONTROL, regval,
> +				      !(regval & ALL_QUEUES_RST), 0, 20))
> +		dev_err(&hci->master.dev, "%s: Reset queues failed\n", __func__);
> +}
> +
>  /* located here rather than dct.c because needed bits are in core reg space */
>  void mipi_i3c_hci_dct_index_reset(struct i3c_hci *hci)
>  {
> @@ -1040,7 +1052,8 @@ MODULE_DEVICE_TABLE(acpi, i3c_hci_acpi_match);
>  static const struct platform_device_id i3c_hci_driver_ids[] = {
>  	{ .name = "intel-lpss-i3c", HCI_QUIRK_RPM_ALLOWED |
>  				    HCI_QUIRK_RPM_IBI_ALLOWED |
> -				    HCI_QUIRK_RPM_PARENT_MANAGED },
> +				    HCI_QUIRK_RPM_PARENT_MANAGED |
> +				    HCI_QUIRK_DMA_ABORT_REQUIRES_PIO_RESET },
>  	{ /* sentinel */ }
>  };
>  MODULE_DEVICE_TABLE(platform, i3c_hci_driver_ids);
> diff --git a/drivers/i3c/master/mipi-i3c-hci/dma.c b/drivers/i3c/master/mipi-i3c-hci/dma.c
> index 268f54b32101..699c6d523eed 100644
> --- a/drivers/i3c/master/mipi-i3c-hci/dma.c
> +++ b/drivers/i3c/master/mipi-i3c-hci/dma.c
> @@ -597,6 +597,13 @@ static void hci_dma_xfer_done(struct i3c_hci *hci, struct hci_rh_data *rh)
>  	rh_reg_write(RING_OPERATION1, op1_val);
>  }
>
> +static void hci_dma_abort_requires_pio_reset_quirk(struct i3c_hci *hci, struct hci_rh_data *rh)
> +{
> +	if ((hci->quirks & HCI_QUIRK_DMA_ABORT_REQUIRES_PIO_RESET) &&
> +	    (rh_reg_read(RING_STATUS) & RING_STATUS_ABORTED))
> +		mipi_i3c_hci_pio_reset_all_queues(hci);
> +}
> +
>  static void hci_dma_unblock_enqueue(struct i3c_hci *hci)
>  {
>  	if (hci->enqueue_blocked) {
> @@ -638,6 +645,8 @@ static bool hci_dma_dequeue_xfer(struct i3c_hci *hci,
>  		}
>  	}
>
> +	hci_dma_abort_requires_pio_reset_quirk(hci, rh);
> +

If only use once, needn't helper function since this helper function is
simple

Frank
>  	hci_dma_xfer_done(hci, rh);
>
>  	for (i = 0; i < n; i++) {
> diff --git a/drivers/i3c/master/mipi-i3c-hci/hci.h b/drivers/i3c/master/mipi-i3c-hci/hci.h
> index 83d4f13a68a3..01237b12d32e 100644
> --- a/drivers/i3c/master/mipi-i3c-hci/hci.h
> +++ b/drivers/i3c/master/mipi-i3c-hci/hci.h
> @@ -156,10 +156,12 @@ struct i3c_hci_dev_data {
>  #define HCI_QUIRK_RPM_ALLOWED		BIT(5)  /* Runtime PM allowed */
>  #define HCI_QUIRK_RPM_IBI_ALLOWED	BIT(6)  /* IBI and Hot-Join allowed while runtime suspended */
>  #define HCI_QUIRK_RPM_PARENT_MANAGED	BIT(7)  /* Runtime PM managed by parent device */
> +#define HCI_QUIRK_DMA_ABORT_REQUIRES_PIO_RESET	BIT(8)  /* Do PIO queue SW resets after DMA abort */
>
>  /* global functions */
>  void mipi_i3c_hci_resume(struct i3c_hci *hci);
>  void mipi_i3c_hci_pio_reset(struct i3c_hci *hci);
> +void mipi_i3c_hci_pio_reset_all_queues(struct i3c_hci *hci);
>  void mipi_i3c_hci_dct_index_reset(struct i3c_hci *hci);
>  void amd_set_od_pp_timing(struct i3c_hci *hci);
>  void amd_set_resp_buf_thld(struct i3c_hci *hci);
> --
> 2.51.0
>

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