Re: [PATCH v4 3/7] PCI/MSI: Introduce __pcim_enable_msi_range()

[Philipp Stanner <phasta@mailbox.org>]

On Fri, 2026-04-24 at 15:57 +0800, Shawn Lin wrote:
> Introduce __pcim_enable_msi_range(), a devres-managed variant of
> __pci_enable_msi_range(). The new function provides automatic cleanup
> of MSI interrupts via devres, reducing the risk of resource leaks and
> simplifying driver error handling.
> 
> This function is particularly useful for drivers that already use
> pcim_enable_device() and want consistent devres management for all
> PCI resources, including MSI interrupts.
> 
> Drivers can replace calls to __pci_enable_msi_range() with
> __pcim_enable_msi_range() to benefit from automatic cleanup without
> changing their core logic.
> 
> Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>

Reviewed-by: Philipp Stanner <phasta@kernel.org>

> ---
> 
> Changes in v4: None
> Changes in v3: None
> Changes in v2: None
> 
>  drivers/pci/msi/msi.c | 20 ++++++++++++++++++++
>  drivers/pci/msi/msi.h |  1 +
>  2 files changed, 21 insertions(+)
> 
> diff --git a/drivers/pci/msi/msi.c b/drivers/pci/msi/msi.c
> index 5c196c2..0aaff57 100644
> --- a/drivers/pci/msi/msi.c
> +++ b/drivers/pci/msi/msi.c
> @@ -499,6 +499,26 @@ int __pci_enable_msi_range(struct pci_dev *dev, int minvec, int maxvec,
>  	return pci_msi_range_init(dev, minvec, maxvec, nvec, affd);
>  }
>  
> +int __pcim_enable_msi_range(struct pci_dev *dev, int minvec, int maxvec,
> +			    struct irq_affinity *affd)
> +{
> +	int nvec, rc;
> +
> +	nvec = pci_msi_range_alloc(dev, minvec, maxvec);
> +	if (nvec < 0)
> +		return nvec;
> +
> +	rc = msi_setup_device_data(&dev->dev);
> +	if (rc)
> +		return rc;
> +
> +	rc = devm_add_action(&dev->dev, pcim_msi_release, dev);

OK I guess. But pcim_msi_release also sets the is_msi_managed boolean,
which I think will not be needed anymore long-term? If you agree, I'd
add a TODO for removing that boolean at an appropriate place and patch,
too.


P.

> +	if (rc)
> +		return rc;
> +
> +	return pci_msi_range_init(dev, minvec, maxvec, nvec, affd);
> +}
> +
>  /**
>   * pci_msi_vec_count - Return the number of MSI vectors a device can send
>   * @dev: device to report about
> diff --git a/drivers/pci/msi/msi.h b/drivers/pci/msi/msi.h
> index 0b420b3..81c6b099 100644
> --- a/drivers/pci/msi/msi.h
> +++ b/drivers/pci/msi/msi.h
> @@ -94,6 +94,7 @@ void pci_msi_shutdown(struct pci_dev *dev);
>  void pci_msix_shutdown(struct pci_dev *dev);
>  void pci_free_msi_irqs(struct pci_dev *dev);
>  int __pci_enable_msi_range(struct pci_dev *dev, int minvec, int maxvec, struct irq_affinity *affd);
> +int __pcim_enable_msi_range(struct pci_dev *dev, int minvec, int maxvec, struct irq_affinity *affd);
>  int __pci_enable_msix_range(struct pci_dev *dev, struct msix_entry *entries, int minvec,
>  			    int maxvec,  struct irq_affinity *affd, int flags);
>  void __pci_restore_msi_state(struct pci_dev *dev);