[PATCH 4.9 114/310] PCI/msi: fix the pci_alloc_irq_vectors_affinity stub

[Greg Kroah-Hartman]

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Christoph Hellwig <hch@xxxxxx>


[ Upstream commit 83b4605b0c16cde5b00c8cf192408d51eab75402 ]

We need to return an error for any call that asks for MSI / MSI-X
vectors only, so that non-trivial fallback logic can work properly.

Also valid dev->irq and use the "correct" errno value based on feedback
from Linus.

Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Reported-by: Steven Rostedt <rostedt@xxxxxxxxxxx>
Fixes: aff17164 ("PCI: Provide sensible IRQ vector alloc/free routines")
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 include/linux/pci.h |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1348,9 +1348,9 @@ static inline int pci_alloc_irq_vectors(
 		unsigned int min_vecs, unsigned int max_vecs,
 		unsigned int flags)
 {
-	if (min_vecs > 1)
-		return -EINVAL;
-	return 1;
+	if ((flags & PCI_IRQ_LEGACY) && min_vecs == 1 && dev->irq)
+		return 1;
+	return -ENOSPC;
 }
 static inline void pci_free_irq_vectors(struct pci_dev *dev)
 {