Re: [PATCH v3 1/4] PCI: Introduce pcim_alloc_irq_vectors()

Krzysztof Wilczyński
2021-02-16T17:54:08Z

Hi Dejin,

> Introduce pcim_alloc_irq_vectors(), a device-managed version of
> pci_alloc_irq_vectors(). Introducing this function can simplify
> the error handling path in many drivers.
>
> And use pci_free_irq_vectors() to replace some code in pcim_release(),
> they are equivalent, and no functional change. It is more explicit
> that pcim_alloc_irq_vectors() is a device-managed function.
[...]

Some suggestions about the commit message as per:

https://lore.kernel.org/linux-pci/YCwE2cf9X%2FGd6lWy@rocinante/

> +/**
> + * pcim_alloc_irq_vectors - a device-managed pci_alloc_irq_vectors()
> + * @dev: PCI device to operate on
> + * @min_vecs: minimum number of vectors required (must be >= 1)
> + * @max_vecs: maximum (desired) number of vectors
> + * @flags: flags or quirks for the allocation
> + *
> + * Return the number of vectors allocated, (which might be smaller than
> + * @max_vecs) if successful, or a negative error code on error. If less
> + * than @min_vecs interrupt vectors are available for @dev the function
> + * will fail with -ENOSPC.
> + *
> + * It depends on calling pcim_enable_device() to make IRQ resources
> + * manageable.
> + */
> +int pcim_alloc_irq_vectors(struct pci_dev *dev, unsigned int min_vecs,
> + unsigned int max_vecs, unsigned int flags)
> +{
> + struct pci_devres *dr;
> +
> + dr = find_pci_dr(dev);
> + if (!dr || !dr->enabled)
> + return -EINVAL;
> +
> + return pci_alloc_irq_vectors(dev, min_vecs, max_vecs, flags);
> +}
> +EXPORT_SYMBOL(pcim_alloc_irq_vectors);
[...]

Looks good! Thank you for adding kernel-doc here! Much appreciated.

Reviewed-by: Krzysztof Wilczyński <kw@linux.com>

Krzysztof