[PATCH V2 07/20] i3c: mipi-i3c-hci: Manage DMA deallocation via devres action

[Frank Li]

On Thu, Jan 08, 2026 at 10:05:45AM +0200, Adrian Hunter wrote:
> The driver already uses devres for resource management, but the standard
> resource-managed DMA allocation helpers cannot be used because they assume
> the DMA device matches the managed device.
>
> To address this, factor out the deallocation logic from hci_dma_cleanup()
> into a new helper, hci_dma_free(), and register it as a devres action.
>
> Signed-off-by: Adrian Hunter <adrian.hunter at intel.com>
> ---

Reviewed-by: Frank Li <Frank.Li at nxp.com>
>
>
> Changes in V2:
>
> 	Move hci_dma_free() below hci_dma_cleanup() to make patch look
> 	better to review
>
> 	Frank suggested using devm_add_action_and_reset() but it doesn't
> 	work because the error path needs to call hci_dma_cleanup() before
> 	hci_dma_free
>
>
>  drivers/i3c/master/mipi-i3c-hci/dma.c | 23 +++++++++++++++++++++--
>  1 file changed, 21 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/i3c/master/mipi-i3c-hci/dma.c b/drivers/i3c/master/mipi-i3c-hci/dma.c
> index 54849aa98fad..4999cf3d9674 100644
> --- a/drivers/i3c/master/mipi-i3c-hci/dma.c
> +++ b/drivers/i3c/master/mipi-i3c-hci/dma.c
> @@ -169,6 +169,22 @@ static void hci_dma_cleanup(struct i3c_hci *hci)
>
>  		rh_reg_write(CR_SETUP, 0);
>  		rh_reg_write(IBI_SETUP, 0);
> +	}
> +
> +	rhs_reg_write(CONTROL, 0);
> +}
> +
> +static void hci_dma_free(void *data)
> +{
> +	struct i3c_hci *hci = data;
> +	struct hci_rings_data *rings = hci->io_data;
> +	struct hci_rh_data *rh;
> +
> +	if (!rings)
> +		return;
> +
> +	for (int i = 0; i < rings->total; i++) {
> +		rh = &rings->headers[i];
>
>  		if (rh->xfer)
>  			dma_free_coherent(rings->sysdev,
> @@ -190,8 +206,6 @@ static void hci_dma_cleanup(struct i3c_hci *hci)
>  		kfree(rh->ibi_data);
>  	}
>
> -	rhs_reg_write(CONTROL, 0);
> -
>  	kfree(rings);
>  	hci->io_data = NULL;
>  }
> @@ -359,10 +373,15 @@ static int hci_dma_init(struct i3c_hci *hci)
>  					   RING_CTRL_RUN_STOP);
>  	}
>
> +	ret = devm_add_action(hci->master.dev.parent, hci_dma_free, hci);
> +	if (ret)
> +		goto err_out;
> +
>  	return 0;
>
>  err_out:
>  	hci_dma_cleanup(hci);
> +	hci_dma_free(hci);
>  	return ret;
>  }
>
> --
> 2.51.0
>
>
> --
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