From 660661afcd40ed7f515ef3369721ed58e80c0fc5 Mon Sep 17 00:00:00 2001
From: Victor Gu <xigu@marvell.com>
Date: Fri, 6 Apr 2018 16:55:31 +0200
Subject: [PATCH] PCI: aardvark: Fix logic in advk_pcie_{rd,wr}_conf()
Git-commit: 660661afcd40ed7f515ef3369721ed58e80c0fc5
Patch-mainline: v4.17-rc3
References: bsc#1051510

The PCI configuration space read/write functions were special casing
the situation where PCI_SLOT(devfn) != 0, and returned
PCIBIOS_DEVICE_NOT_FOUND in this case.

However, while this is what is intended for the root bus, it is not
intended for the child busses, as it prevents discovering devices with
PCI_SLOT(x) != 0. Therefore, we return PCIBIOS_DEVICE_NOT_FOUND only
if we're on the root bus.

Fixes: 8c39d710363c1 ("PCI: aardvark: Add Aardvark PCI host controller driver")
Cc: <stable@vger.kernel.org>
Signed-off-by: Victor Gu <xigu@marvell.com>
Reviewed-by: Wilson Ding <dingwei@marvell.com>
Reviewed-by: Nadav Haklai <nadavh@marvell.com>
[thomas: tweak commit log.]
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/pci/host/pci-aardvark.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/pci/host/pci-aardvark.c b/drivers/pci/host/pci-aardvark.c
index b04d37b3c5de..b72f15c99793 100644
--- a/drivers/pci/host/pci-aardvark.c
+++ b/drivers/pci/host/pci-aardvark.c
@@ -437,7 +437,7 @@ static int advk_pcie_rd_conf(struct pci_bus *bus, u32 devfn,
 	u32 reg;
 	int ret;
 
-	if (PCI_SLOT(devfn) != 0) {
+	if ((bus->number == pcie->root_bus_nr) && PCI_SLOT(devfn) != 0) {
 		*val = 0xffffffff;
 		return PCIBIOS_DEVICE_NOT_FOUND;
 	}
@@ -491,7 +491,7 @@ static int advk_pcie_wr_conf(struct pci_bus *bus, u32 devfn,
 	int offset;
 	int ret;
 
-	if (PCI_SLOT(devfn) != 0)
+	if ((bus->number == pcie->root_bus_nr) && PCI_SLOT(devfn) != 0)
 		return PCIBIOS_DEVICE_NOT_FOUND;
 
 	if (where % size)
-- 
2.18.0