| Message ID | 1473577767-9888-1-git-send-email-hch@lst.de (mailing list archive) |
|---|---|
| State | New, archived |
| Delegated to: | Bjorn Helgaas |
| Headers | show |
Hi Christoph, On Sun, Sep 11, 2016 at 09:09:27AM +0200, Christoph Hellwig wrote: > Alex pointed out that we might want to use pci_intx_for_msi in > pci_alloc_irq_vectors for the case where allocating MSI or MSI-X vectors > fails completely. I tried to read up the history behind pci_intx_for_msi, > but the changelogs seem a bit confusing, e.g. the comment in the tg3 > around that code that was replaced by this quirk only talk about > _disabling_ INT-X. Maybe someone can help me to shed some light about > this workaround, and help answering the question wether we need it > in this case. If we want to do this, I'd like to have a changelog that explains *why*, so I'm ignoring it for now. I'm not nacking it; I just don't understand why we should do it yet, and I'm too lazy to do all the research myself. > Signed-off-by: Christoph Hellwig <hch@lst.de> > Cc: David Miller <davem@davemloft.net> > Cc: Shane Huang <shane.huang@amd.com> > --- > drivers/pci/msi.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c > index 9da5ecb..a4b443f 100644 > --- a/drivers/pci/msi.c > +++ b/drivers/pci/msi.c > @@ -1215,7 +1215,7 @@ 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) { > - pci_intx(dev, 1); > + pci_intx_for_msi(dev, 1); > return 1; > } > > -- > 2.1.4 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-pci" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Tue, Sep 20, 2016 at 02:46:14PM -0500, Bjorn Helgaas wrote: > If we want to do this, I'd like to have a changelog that explains > *why*, so I'm ignoring it for now. I'm not nacking it; I just don't > understand why we should do it yet, and I'm too lazy to do all the > research myself. Can't blame you. Alex pointed me to the function, and it seems like a good idea, but research in git history just doesn't give me an conclusive reason on why to do it either. -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c index 9da5ecb..a4b443f 100644 --- a/drivers/pci/msi.c +++ b/drivers/pci/msi.c @@ -1215,7 +1215,7 @@ 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) { - pci_intx(dev, 1); + pci_intx_for_msi(dev, 1); return 1; }
Alex pointed out that we might want to use pci_intx_for_msi in pci_alloc_irq_vectors for the case where allocating MSI or MSI-X vectors fails completely. I tried to read up the history behind pci_intx_for_msi, but the changelogs seem a bit confusing, e.g. the comment in the tg3 around that code that was replaced by this quirk only talk about _disabling_ INT-X. Maybe someone can help me to shed some light about this workaround, and help answering the question wether we need it in this case. Signed-off-by: Christoph Hellwig <hch@lst.de> Cc: David Miller <davem@davemloft.net> Cc: Shane Huang <shane.huang@amd.com> --- drivers/pci/msi.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)