The root bus checks rework in:
commit d84c572de1a3 ("PCI: rockchip: Use pci_is_root_bus() to check if bus is root bus")
caused a regression whereby in rockchip_pcie_valid_device() if
the bus parameter is the root bus and the dev value == 0 the
function should return 1 (ie true) without checking if the
bus->parent pointer is a root bus because that triggers a NULL
pointer dereference.
Fix this by streamlining the root bus detection.
Fixes: d84c572de1a3 ("PCI: rockchip: Use pci_is_root_bus() to check if bus is root bus")
Reported-by: Samuel Dionne-Riel <samuel@xxxxxxxxxxxxxxx>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx>
Cc: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Cc: Rob Herring <robh@xxxxxxxxxx>
Cc: Shawn Lin <shawn.lin@xxxxxxxxxxxxxx>
---
drivers/pci/controller/pcie-rockchip-host.c | 11 ++++-------
1 file changed, 4 insertions(+), 7 deletions(-)
diff --git a/drivers/pci/controller/pcie-rockchip-host.c b/drivers/pci/controller/pcie-rockchip-host.c
index 0bb2fb3e8a0b..9705059523a6 100644
--- a/drivers/pci/controller/pcie-rockchip-host.c
+++ b/drivers/pci/controller/pcie-rockchip-host.c
@@ -71,16 +71,13 @@ static void rockchip_pcie_update_txcredit_mui(struct rockchip_pcie *rockchip)
static int rockchip_pcie_valid_device(struct rockchip_pcie *rockchip,
struct pci_bus *bus, int dev)
{
- /* access only one slot on each root port */
- if (pci_is_root_bus(bus) && dev > 0)
- return 0;
-
/*
- * do not read more than one device on the bus directly attached
+ * Access only one slot on each root port.
+ * Do not read more than one device on the bus directly attached
* to RC's downstream side.
*/
- if (pci_is_root_bus(bus->parent) && dev > 0)
- return 0;
+ if (pci_is_root_bus(bus) || pci_is_root_bus(bus->parent))
+ return dev == 0;
return 1;
}
--
2.26.1
