Re: [PATCH v3 5/5] PCI: dwc: Implement endpoint DMA channel delegation

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Low] Calls to undeclared and undefined functions `dw_edma_request_delegated_chan` and `dw_edma_release_delegated_chan` will cause compilation and linking failures.
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commit e55470d381c0b56d92a5e22c376824161b53e132
Author: Koichiro Den <den@valinux.co.jp>

PCI: dwc: Implement endpoint DMA channel delegation

This commit implements the EPC DMA channel delegation operations for
DesignWare endpoint controllers. It uses the local eDMA provider to reserve
hardware channels and returns them as opaque handles, limiting delegation
to PF0 and handling reclamation.

> diff --git a/drivers/pci/controller/dwc/pcie-designware-ep.c b/drivers/pci/controller/dwc/pcie-designware-ep.c
> --- a/drivers/pci/controller/dwc/pcie-designware-ep.c
> +++ b/drivers/pci/controller/dwc/pcie-designware-ep.c

[ ... ]

> +static int dw_pcie_ep_delegate_dma_chan(struct pci_epc *epc, u8 func_no,
> +					u8 vfunc_no,
> +					enum pci_epc_aux_dma_dir dir, u16 hw_ch,
> +					void **data)
> +{

[ ... ]

> +	switch (dir) {
> +	case PCI_EPC_AUX_DMA_EP_TO_RC:
> +		if (hw_ch >= edma->ll_wr_cnt)
> +			return -EINVAL;
> +		write = true;
> +		break;
> +	case PCI_EPC_AUX_DMA_RC_TO_EP:
> +		if (hw_ch >= edma->ll_rd_cnt)
> +			return -EINVAL;
> +		write = false;
> +		break;
> +	default:
> +		return -EINVAL;
> +	}
> +
> +	chan = dw_edma_request_delegated_chan(edma->dev, write, hw_ch);

[Severity: Low]
Are the definitions for dw_edma_request_delegated_chan() missing from this
commit? Calling undeclared and undefined functions in
dw_pcie_ep_delegate_dma_chan() will result in compilation and linking
failures.

> +	if (!chan)
> +		return -EBUSY;
> +
> +	*data = chan;
> +
> +	return 0;
> +}
> +
> +static void dw_pcie_ep_reclaim_dma_chan(struct pci_epc *epc, u8 func_no,
> +					u8 vfunc_no, void *data, bool quiesce)
> +{
> +	dw_edma_release_delegated_chan(data, quiesce);

[Severity: Low]
Does this code also rely on an undefined function? Like the request function
above, dw_edma_release_delegated_chan() appears to be undeclared in the
kernel tree at this point, which will break the build.

> +}

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260620170438.3756593-1-den@valinux.co.jp?part=5