[GIT PULL] IRQ fix

[Ingo Molnar]

Linus,

Please pull the latest irq-urgent-for-linus git tree from:

   git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git 
irq-urgent-for-linus

   # HEAD: f3b0946d629c8bfbd3e5f038e30cb9c711a35f10 genirq/msi: Make sure PCI 
MSIs are activated early

A fix for an MSI regression.

 Thanks,

        Ingo

------------------>
Marc Zyngier (1):
      genirq/msi: Make sure PCI MSIs are activated early


 drivers/pci/msi.c   |  2 ++
 include/linux/msi.h |  2 ++
 kernel/irq/msi.c    | 11 +++++++++++
 3 files changed, 15 insertions(+)

diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index a02981efdad5..eafa6138a6b8 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -1411,6 +1411,8 @@ struct irq_domain *pci_msi_create_irq_domain(struct 
fwnode_handle *fwnode,
        if (info->flags & MSI_FLAG_USE_DEF_CHIP_OPS)
                pci_msi_domain_update_chip_ops(info);
 
+       info->flags |= MSI_FLAG_ACTIVATE_EARLY;
+
        domain = msi_create_irq_domain(fwnode, info, parent);
        if (!domain)
                return NULL;
diff --git a/include/linux/msi.h b/include/linux/msi.h
index 4f0bfe5912b2..e8c81fbd5f9c 100644
--- a/include/linux/msi.h
+++ b/include/linux/msi.h
@@ -270,6 +270,8 @@ enum {
        MSI_FLAG_MULTI_PCI_MSI          = (1 << 2),
        /* Support PCI MSIX interrupts */
        MSI_FLAG_PCI_MSIX               = (1 << 3),
+       /* Needs early activate, required for PCI */
+       MSI_FLAG_ACTIVATE_EARLY         = (1 << 4),
 };
 
 int msi_domain_set_affinity(struct irq_data *data, const struct cpumask *mask,
diff --git a/kernel/irq/msi.c b/kernel/irq/msi.c
index 54999350162c..19e9dfbe97fa 100644
--- a/kernel/irq/msi.c
+++ b/kernel/irq/msi.c
@@ -359,6 +359,17 @@ int msi_domain_alloc_irqs(struct irq_domain *domain, 
struct device *dev,
                else
                        dev_dbg(dev, "irq [%d-%d] for MSI\n",
                                virq, virq + desc->nvec_used - 1);
+               /*
+                * This flag is set by the PCI layer as we need to activate
+                * the MSI entries before the PCI layer enables MSI in the
+                * card. Otherwise the card latches a random msi message.
+                */
+               if (info->flags & MSI_FLAG_ACTIVATE_EARLY) {
+                       struct irq_data *irq_data;
+
+                       irq_data = irq_domain_get_irq_data(domain, desc->irq);
+                       irq_domain_activate_irq(irq_data);
+               }
        }
 
        return 0;