Hi Dejin,
Thank you for all the work here!
The subject and the commit message could be improved to include a little
more details about why do you want to do it, and what problems does it
aims to solve.
> Introduce pcim_alloc_irq_vectors(), a explicit device-managed version of
> pci_alloc_irq_vectors().
You can probably drop the "explicit" word from the sentence above.
> +/**
> + * pcim_alloc_irq_vectors - a device-managed pci_alloc_irq_vectors()
> + *
> + * It depends on calling pcim_enable_device() to make irq resources manageable.
> + */
It would be "IRQ" in the sentence above. Also see [1] for more details
about how to make a patch ready to be accepted.
Also, this comment looks like it's intended to be compliant with the
kernel-doc format, and if so, then you should describe each argument as
the bare minimum, so that the entire comment would become this function
documentation making it also a little more useful. See [2] for an
example of how to use kernel-doc.
> +int pcim_alloc_irq_vectors(struct pci_dev *dev, unsigned int min_vecs,
> + unsigned int max_vecs, unsigned int flags)
> +{
> + struct pci_devres *dr;
> +
> + /*Ensure that the pcim_enable_device() function has been called*/
The comment above has to be correctly aligned and it's also missing
spaces around the sentence to be properly formatted, see [3].
> + dr = find_pci_dr(dev);
> + if (!dr || !dr->enabled)
> + return -EINVAL;
> +
> + return pci_alloc_irq_vectors(dev, min_vecs, max_vecs, flags);
> +}
Question: wouldn't you need to call pci_free_irq_vectors() somewhere,
possibly to pcim_release() callback? Although, I am not sure where the
right place would be.
I am asking, as the documentation (see [4]) suggests that one would have
to release allocated IRQ vectors (relevant exceprt):
>> To automatically use MSI or MSI-X interrupt vectors, use the following
>> function:
>>
>> int pci_alloc_irq_vectors(struct pci_dev *dev, unsigned int min_vecs,
>> unsigned int max_vecs, unsigned int flags);
>>
>> which allocates up to max_vecs interrupt vectors for a PCI device.
>>
>> (...)
>>
>> Any allocated resources should be freed before removing the device using
>> the following function:
>>
>> void pci_free_irq_vectors(struct pci_dev *dev);
What do you think?
1. https://lore.kernel.org/linux-pci/20171026223701.GA25649@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx/
2. https://www.kernel.org/doc/html/latest/doc-guide/kernel-doc.html
3. https://www.kernel.org/doc/html/latest/process/coding-style.html
4. https://www.kernel.org/doc/html/latest/PCI/msi-howto.html
Krzysztof
