[PATCH 4.19 175/287] powerpc/pci: Fix PHB numbering when using opal-phbid

[Greg Kroah-Hartman]

From: Michael Ellerman <mpe@xxxxxxxxxxxxxx>

[ Upstream commit f4b39e88b42d13366b831270306326b5c20971ca ]

The recent change to the PHB numbering logic has a logic error in the
handling of "ibm,opal-phbid".

When an "ibm,opal-phbid" property is present, &prop is written to and
ret is set to zero.

The following call to of_alias_get_id() is skipped because ret == 0.

But then the if (ret >= 0) is true, and the body of that if statement
sets prop = ret which throws away the value that was just read from
"ibm,opal-phbid".

Fix the logic by only doing the ret >= 0 check in the of_alias_get_id()
case.

Fixes: 0fe1e96fef0a ("powerpc/pci: Prefer PCI domain assignment via DT 'linux,pci-domain' and alias")
Reviewed-by: Pali Rohár <pali@xxxxxxxxxx>
Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20220802105723.1055178-1-mpe@xxxxxxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 arch/powerpc/kernel/pci-common.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/arch/powerpc/kernel/pci-common.c b/arch/powerpc/kernel/pci-common.c
index b0bd55f2ce3a..740dcbdd56d8 100644
--- a/arch/powerpc/kernel/pci-common.c
+++ b/arch/powerpc/kernel/pci-common.c
@@ -98,11 +98,13 @@ static int get_phb_number(struct device_node *dn)
 	}
 	if (ret)
 		ret = of_property_read_u64(dn, "ibm,opal-phbid", &prop);
-	if (ret)
+
+	if (ret) {
 		ret = of_alias_get_id(dn, "pci");
-	if (ret >= 0) {
-		prop = ret;
-		ret = 0;
+		if (ret >= 0) {
+			prop = ret;
+			ret = 0;
+		}
 	}
 	if (ret) {
 		u32 prop_32;
-- 
2.35.1