From 5d0bdf2867825a92c0a563957a2fb059149ab0d4 Mon Sep 17 00:00:00 2001
From: Christoph Hellwig <hch@lst.de>
Date: Thu, 11 Aug 2016 07:11:05 -0700
Subject: [PATCH] PCI: Call pci_intx() when using legacy interrupts in
pci_alloc_irq_vectors()
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 it seems safe and useful
to add this call to pci_alloc_irq_vectors() so that ahci can just use
pci_alloc_irq_vectors().
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
---
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 9233e7f62f47..593698e11f96 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);
return 1;
+ }
+
return vecs;
}
EXPORT_SYMBOL(pci_alloc_irq_vectors);
--
2.30.2