[PATCH 5.16 0785/1039] PCI: dwc: Do not remap invalid res

[Greg Kroah-Hartman]

From: Tim Harvey <tharvey@xxxxxxxxxxxxx>

[ Upstream commit 6e5ebc96ec651b67131f816d7e3bf286c635e749 ]

On imx6 and perhaps others when pcie probes you get a:
imx6q-pcie 33800000.pcie: invalid resource

This occurs because the atu is not specified in the DT and as such it
should not be remapped.

Link: https://lore.kernel.org/r/20211101180243.23761-1-tharvey@xxxxxxxxxxxxx
Fixes: 281f1f99cf3a ("PCI: dwc: Detect number of iATU windows")
Signed-off-by: Tim Harvey <tharvey@xxxxxxxxxxxxx>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx>
Reviewed-by: Rob Herring <robh@xxxxxxxxxx>
Acked-by: Richard Zhu <hongxing.zhu@xxxxxxx>
Cc: Richard Zhu <hongxing.zhu@xxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/pci/controller/dwc/pcie-designware.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c
index 850b4533f4ef5..d92c8a25094fa 100644
--- a/drivers/pci/controller/dwc/pcie-designware.c
+++ b/drivers/pci/controller/dwc/pcie-designware.c
@@ -672,10 +672,11 @@ void dw_pcie_iatu_detect(struct dw_pcie *pci)
 		if (!pci->atu_base) {
 			struct resource *res =
 				platform_get_resource_byname(pdev, IORESOURCE_MEM, "atu");
-			if (res)
+			if (res) {
 				pci->atu_size = resource_size(res);
-			pci->atu_base = devm_ioremap_resource(dev, res);
-			if (IS_ERR(pci->atu_base))
+				pci->atu_base = devm_ioremap_resource(dev, res);
+			}
+			if (!pci->atu_base || IS_ERR(pci->atu_base))
 				pci->atu_base = pci->dbi_base + DEFAULT_DBI_ATU_OFFSET;
 		}
 
-- 
2.34.1