PCI: of: Don't fail devm_pci_alloc_host_bridge() on missing 'ranges'

[ Upstream commit d277f6e ]

Commit 669cbc7 ("PCI: Move DT resource setup into
devm_pci_alloc_host_bridge()") made devm_pci_alloc_host_bridge() fail on
any DT resource parsing errors, but Broadcom iProc uses
devm_pci_alloc_host_bridge() on BCMA bus devices that don't have DT
resources. In particular, there is no 'ranges' property. Fix iProc by
making 'ranges' optional.

If 'ranges' is required by a platform, there's going to be more errors
latter on if it is missing.

Link: https://lore.kernel.org/r/20210803215656.3803204-1-robh@kernel.org
Fixes: 669cbc7 ("PCI: Move DT resource setup into devm_pci_alloc_host_bridge()")
Reported-by: Rafał Miłecki <zajec5@gmail.com>
Tested-by: Rafał Miłecki <rafal@milecki.pl>
Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Srinath Mannam <srinath.mannam@broadcom.com>
Cc: Roman Bacik <roman.bacik@broadcom.com>
Cc: Bharat Gooty <bharat.gooty@broadcom.com>
Cc: Abhishek Shah <abhishek.shah@broadcom.com>
Cc: Jitendra Bhivare <jitendra.bhivare@broadcom.com>
Cc: Ray Jui <ray.jui@broadcom.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: BCM Kernel Feedback <bcm-kernel-feedback-list@broadcom.com>
Cc: Scott Branden <sbranden@broadcom.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

drivers/pci/of.c

@@ -310,7 +310,7 @@ static int devm_of_pci_get_host_bridge_resources(struct device *dev,
 	/* Check for ranges property */
 	err = of_pci_range_parser_init(&parser, dev_node);
 	if (err)
-		goto failed;
+		return 0;
 
 	dev_dbg(dev, "Parsing ranges property...\n");
 	for_each_of_pci_range(&parser, &range) {