Re: [PATCH v1 1/4] PCI: Introduce pcim_alloc_irq_vectors()

From: Krzysztof Wilczyński
Date: Tue Feb 16 2021 - 09:43:18 EST


Hi Dejin and Andy,

[...]
> > > 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):
> >
> > It's done in pcim_release() but not explicitly.
> >
> > if (dev->msi_enabled)
> > pci_disable_msi(dev);
> > if (dev->msix_enabled)
> > pci_disable_msix(dev);
> >
> > Maybe above can be replaced by pci_free_irq_vectors() to be sure that any
> > future change to PCI IRQ allocation APIs.
> >
> > Yes, I have checked and currently the above code is equivalent to
> > pci_free_irq_vectors().
> >
> > Dejin, please update your patch accordingly.
> >
> Hi Andy and Krzysztof,
>
> I have modified it and sent patch v2. thank you very much!

Thank you Andy for double-checking! Much appreciated.

Moving to pci_free_irq_vectors() directly looks great as we are also
removing the surplus checks that pcim_release() is doing - since both
the pci_disable_msi() and the pci_disable_msix() are doing internal
validation to see whether MSI/MSI-X is currently enabled.

Thank you again, Dejin and Andy. :)

Krzysztof