[PATCH resend] PCI: designware: fix register access before host init

[Lucas Stach <l.stach@pengutronix.de>]

The function used to determine if iATU unroll is available will read
a RC register. This is not possible and will result in a system hang
if the RC is still in reset, so it is only safe to call this function
after host_init() has been called.

Fixes: a0601a470537 (PCI: designware: Add iATU Unroll feature)
Reported-by: Gary Bisson <gary.bisson@boundarydevices.com>
Tested-by: Gary Bisson <gary.bisson@boundarydevices.com>
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
---
 drivers/pci/host/pcie-designware.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/pci/host/pcie-designware.c b/drivers/pci/host/pcie-designware.c
index 035f50c03281..74510508fafc 100644
--- a/drivers/pci/host/pcie-designware.c
+++ b/drivers/pci/host/pcie-designware.c
@@ -637,11 +637,11 @@ int dw_pcie_host_init(struct pcie_port *pp)
 		}
 	}
 
-	pp->iatu_unroll_enabled = dw_pcie_iatu_unroll_enabled(pp);
-
 	if (pp->ops->host_init)
 		pp->ops->host_init(pp);
 
+	pp->iatu_unroll_enabled = dw_pcie_iatu_unroll_enabled(pp);
+
 	pp->root_bus_nr = pp->busn->start;
 	if (IS_ENABLED(CONFIG_PCI_MSI)) {
 		bus = pci_scan_root_bus_msi(pp->dev, pp->root_bus_nr,
-- 
2.9.3