[PATCH v2] PCI: host-generic: Avoid reporting incorrect "missing "reg" property" error

[Jess <jess@jessie.cafe>]

When the function pci_host_common_ecam_create() calls
of_address_to_resource() it assumes all errors from that callsite are due
to a missing "reg" property in the device tree node.

This can manifest when running the qemu "virt" board, with a 32-bit kernel
and `highmem=on`.

After the following calls:
of_address_to_resource()
  -> __of_address_to_resource()
  -> __of_address_resource_bounds()

this overflow check can fail due to PCI being out of range:
if (overflows_type(start, r->start))
	return -EOVERFLOW;

This leads to the very confusing error message:
pci-host-generic 4010000000.pcie: host bridge /pcie@10000000 ranges:
pci-host-generic 4010000000.pcie:       IO 0x003eff0000..0x003effffff -> 0x0000000000
pci-host-generic 4010000000.pcie:      MEM 0x0010000000..0x003efeffff -> 0x0010000000
pci-host-generic 4010000000.pcie:      MEM 0x8000000000..0xffffffffff -> 0x8000000000
pci-host-generic 4010000000.pcie: missing "reg" property
pci-host-generic 4010000000.pcie: probe with driver pci-host-generic failed with error -75

Make the error message more generic.

Link: https://www.qemu.org/docs/master/system/arm/virt.html
Signed-off-by: Jess <jess@jessie.cafe>
---
 drivers/pci/controller/pci-host-common.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/pci/controller/pci-host-common.c b/drivers/pci/controller/pci-host-common.c
index c473e7c03bac..d6258c1cffe5 100644
--- a/drivers/pci/controller/pci-host-common.c
+++ b/drivers/pci/controller/pci-host-common.c
@@ -32,7 +32,7 @@ struct pci_config_window *pci_host_common_ecam_create(struct device *dev,
 
 	err = of_address_to_resource(dev->of_node, 0, &cfgres);
 	if (err) {
-		dev_err(dev, "missing \"reg\" property\n");
+		dev_err(dev, "missing or malformed \"reg\" property\n");
 		return ERR_PTR(err);
 	}
 
-- 
2.51.2