On Mon, 25 Jul 2016, Bjorn Helgaas wrote: > On Mon, Jul 25, 2016 at 09:45:13AM +0200, Thomas Gleixner wrote: > I thought the original issue [1] was that PCI_MSI_FLAGS_ENABLE was being > written before PCI_MSI_ADDRESS_LO. That doesn't sound like a good > idea to me. Well. That's only a problem if the PCI device does not support masking. But yes, we missed that case back then. > That does seem like a problem. Maybe it would be better to delay > setting PCI_MSI_FLAGS_ENABLE until after the MSI address & data bits > have been set? I thought about that, but that gets ugly pretty fast. Here is an alternative solution. I think that's the proper place to do it _AFTER_ the hierarchical allocation took place. On x86 Marc's ACTIVATE_EARLY flag would not work because the message is not yet ready to be assembled. Thanks, tglx --- diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c index a080f4496fe2..142341f8331b 100644 --- a/drivers/pci/msi.c +++ b/drivers/pci/msi.c @@ -645,6 +645,15 @@ static int msi_capability_init(struct pci_dev *dev, int nvec) return ret; } + /* + * The mask can be ignored and PCI 2.3 does not specify mask bits for + * each MSI interrupt. So in case of hierarchical irqdomains we need + * to make sure that if masking is not available that the msi message + * is written prior to setting the MSI enable bit in the device. + */ + if (pci_msi_ignore_mask || !entry->msi_attrib.maskbit) + irq_domain_activate_irq(irq_get_irq_data(entry->irq)); + /* Set MSI enabled bits */ pci_intx_for_msi(dev, 0); pci_msi_set_enable(dev, 1); -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
