Re: [PATCH v3 12/13] dmaengine: dw-edma-pcie: Handle optional data blocks

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:

Pre-existing issues:
- [High] Missing pci_free_irq_vectors() in error paths after successful pci_alloc_irq_vectors() causes IRQ resource leaks.
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commit 4c520b14ae411615c26fba953ffdb3c7f374c19a
Author: Koichiro Den <den@valinux.co.jp>

dmaengine: dw-edma-pcie: Handle optional data blocks

This commit skips data block BAR mapping and debug output when a channel
has no data block size. This prepares the driver for future metadata
providers where a zero-sized data block indicates it is not present.

> diff --git a/drivers/dma/dw-edma/dw-edma-pcie.c b/drivers/dma/dw-edma/dw-edma-pcie.c
> index 62740c8c3f939..622ec974a521e 100644
> --- a/drivers/dma/dw-edma/dw-edma-pcie.c
> +++ b/drivers/dma/dw-edma/dw-edma-pcie.c
[ ... ]
> @@ -498,6 +500,9 @@ static int dw_edma_pcie_probe(struct pci_dev *pdev,
>  							  ll_block);
>  		ll_region->sz = ll_block->sz;
>  
> +		if (!dt_block->sz)
> +			continue;
> +
>  		dt_region->vaddr.io = pcim_iomap_table(pdev)[dt_block->bar];
>  		if (!dt_region->vaddr.io)
>  			return -ENOMEM;

[Severity: High]
This isn't a bug introduced by this patch, but does this error path (and
several others in this function) leak IRQ vectors?

Earlier in dw_edma_pcie_probe(), pci_alloc_irq_vectors() is called to allocate
the IRQ vectors. However, multiple subsequent error paths, such as this return
when pcim_iomap_table(pdev) returns NULL, return an error directly without
cleaning up the allocated IRQ vectors.

There are also similar error paths later in the function that fail to call
pci_free_irq_vectors(), such as:

	if (!pci_dev_msi_enabled(pdev)) {
		pci_err(pdev, "enable interrupt failed\n");
		return -EPERM;
	}

and:

	err = dw_edma_probe(chip);
	if (err) {
		pci_err(pdev, "eDMA probe failed\n");
		return err;
	}

Since the driver manually frees these vectors in dw_edma_pcie_remove(), should
the probe function also perform its own cleanup on failure to prevent IRQ
resource exhaustion?

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Sashiko AI review · https://sashiko.dev/#/patchset/20260620170040.3756043-1-den@valinux.co.jp?part=12