PCI: rockchip: Propagate errors for optional regulators

regulator_get_optional() can fail for a number of reasons besides probe
deferral. It can for example return -ENOMEM if it runs out of memory as
it tries to allocate data structures. Propagating only -EPROBE_DEFER is
problematic because it results in these legitimately fatal errors being
treated as "regulator not specified in DT".

What we really want is to ignore the optional regulators only if they
have not been specified in DT. regulator_get_optional() returns -ENODEV
in this case, so that's the special case that we need to handle. So we
propagate all errors, except -ENODEV, so that real failures will still
cause the driver to fail probe.
Tested-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Andrew Murray <andrew.murray@arm.com>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Acked-by: Shawn Lin <shawn.lin@rock-chips.com>
Cc: Shawn Lin <shawn.lin@rock-chips.com>
Cc: Heiko Stuebner <heiko@sntech.de>
Cc: linux-rockchip@lists.infradead.org

drivers/pci/controller/pcie-rockchip-host.c

@@ -608,29 +608,29 @@ static int rockchip_pcie_parse_host_dt(struct rockchip_pcie *rockchip)
 
 	rockchip->vpcie12v = devm_regulator_get_optional(dev, "vpcie12v");
 	if (IS_ERR(rockchip->vpcie12v)) {
-		if (PTR_ERR(rockchip->vpcie12v) == -EPROBE_DEFER)
-			return -EPROBE_DEFER;
+		if (PTR_ERR(rockchip->vpcie12v) != -ENODEV)
+			return PTR_ERR(rockchip->vpcie12v);
 		dev_info(dev, "no vpcie12v regulator found\n");
 	}
 
 	rockchip->vpcie3v3 = devm_regulator_get_optional(dev, "vpcie3v3");
 	if (IS_ERR(rockchip->vpcie3v3)) {
-		if (PTR_ERR(rockchip->vpcie3v3) == -EPROBE_DEFER)
-			return -EPROBE_DEFER;
+		if (PTR_ERR(rockchip->vpcie3v3) != -ENODEV)
+			return PTR_ERR(rockchip->vpcie3v3);
 		dev_info(dev, "no vpcie3v3 regulator found\n");
 	}
 
 	rockchip->vpcie1v8 = devm_regulator_get_optional(dev, "vpcie1v8");
 	if (IS_ERR(rockchip->vpcie1v8)) {
-		if (PTR_ERR(rockchip->vpcie1v8) == -EPROBE_DEFER)
-			return -EPROBE_DEFER;
+		if (PTR_ERR(rockchip->vpcie1v8) != -ENODEV)
+			return PTR_ERR(rockchip->vpcie1v8);
 		dev_info(dev, "no vpcie1v8 regulator found\n");
 	}
 
 	rockchip->vpcie0v9 = devm_regulator_get_optional(dev, "vpcie0v9");
 	if (IS_ERR(rockchip->vpcie0v9)) {
-		if (PTR_ERR(rockchip->vpcie0v9) == -EPROBE_DEFER)
-			return -EPROBE_DEFER;
+		if (PTR_ERR(rockchip->vpcie0v9) != -ENODEV)
+			return PTR_ERR(rockchip->vpcie0v9);
 		dev_info(dev, "no vpcie0v9 regulator found\n");
 	}