[PATCH kernel v3] powerpc/pci: Fix broken INTx configuration via OF

[Alexey Kardashevskiy <aik@ozlabs.ru>]

Commit 59f47eff03a0 ("powerpc/pci: Use of_irq_parse_and_map_pci() helper")
replaced of_irq_parse_pci() + irq_create_of_mapping() with
of_irq_parse_and_map_pci() but this change lost virq returned by
irq_create_of_mapping() so virq remained zero causing INTx
misconfiguration.

This fixes pci_read_irq_line() not to loose a virq returned by
of_irq_parse_and_map_pci().

Fixes: 59f47eff03a0 "powerpc/pci: Use of_irq_parse_and_map_pci() helper"
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
---
Changes:
v3:
* change virq from unsigned to int as of_irq_parse_and_map_pci returns int
and even though it only returns non-negative values now, this may change
in the future

v2:
* changed the condition from <=0 to !=0 as by design
of_irq_parse_and_map_pci() can only return 0 for an error and virq>0.
---
 arch/powerpc/kernel/pci-common.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/kernel/pci-common.c b/arch/powerpc/kernel/pci-common.c
index ae2ede4..446c796 100644
--- a/arch/powerpc/kernel/pci-common.c
+++ b/arch/powerpc/kernel/pci-common.c
@@ -362,7 +362,7 @@ struct pci_controller* pci_find_hose_for_OF_device(struct device_node* node)
  */
 static int pci_read_irq_line(struct pci_dev *pci_dev)
 {
-	unsigned int virq = 0;
+	int virq;
 
 	pr_debug("PCI: Try to map irq for %s...\n", pci_name(pci_dev));
 
@@ -370,7 +370,8 @@ static int pci_read_irq_line(struct pci_dev *pci_dev)
 	memset(&oirq, 0xff, sizeof(oirq));
 #endif
 	/* Try to get a mapping from the device-tree */
-	if (!of_irq_parse_and_map_pci(pci_dev, 0, 0)) {
+	virq = of_irq_parse_and_map_pci(pci_dev, 0, 0);
+	if (virq <= 0) {
 		u8 line, pin;
 
 		/* If that fails, lets fallback to what is in the config
-- 
2.11.0