Messages in this thread | | | Date | Thu, 18 Aug 2016 11:20:07 +0200 | From | Alexander Gordeev <> | Subject | Re: [PATCH 2/2] pci: call pci_intx when using legacy interrupts in pci_alloc_irq_vectors |
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On Thu, Aug 11, 2016 at 07:11:05AM -0700, Christoph Hellwig wrote: > ahci currently insists on an explicit call to pci_intx before falling back > from MSI or MSI-X to legacy irqs. As pci_intx is a no-op if the command > register already contains the right value is seems safe and useful to add > this call to pci_alloc_irq_vectors so that ahci can just use > pci_alloc_irq_vectors.
Looking at ahci_init_interrupts() (and probably at commit d684a90d ("ahci: per-port msix support")) it looks like pci_alloc_irq_vectors() is able to preserve the current AHCI logic?
> Signed-off-by: Christoph Hellwig <hch@lst.de> > --- > drivers/pci/msi.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c > index 9233e7f..593698e 100644 > --- a/drivers/pci/msi.c > +++ b/drivers/pci/msi.c > @@ -1200,8 +1200,11 @@ int pci_alloc_irq_vectors(struct pci_dev *dev, unsigned int min_vecs, > } > > /* use legacy irq if allowed */ > - if ((flags & PCI_IRQ_LEGACY) && min_vecs == 1) > + if ((flags & PCI_IRQ_LEGACY) && min_vecs == 1) { > + pci_intx(dev, 1);
It would rather called pci_intx_for_msi() here. But because it is a generic code I am not sure what implications it has for all drivers out there.
> return 1; > + } > + > return vecs; > } > EXPORT_SYMBOL(pci_alloc_irq_vectors); > -- > 2.1.4 >
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