[PATCH 4/5] PCI: histb: Properly handle optional regulators

[Thierry Reding <thierry.reding@gmail.com>]

From: Thierry Reding <treding@nvidia.com>

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.

Cc: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Thierry Reding <treding@nvidia.com>
---
 drivers/pci/controller/dwc/pcie-histb.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/pci/controller/dwc/pcie-histb.c b/drivers/pci/controller/dwc/pcie-histb.c
index 954bc2b74bbc..811b5c6d62ea 100644
--- a/drivers/pci/controller/dwc/pcie-histb.c
+++ b/drivers/pci/controller/dwc/pcie-histb.c
@@ -340,8 +340,8 @@ static int histb_pcie_probe(struct platform_device *pdev)
 
 	hipcie->vpcie = devm_regulator_get_optional(dev, "vpcie");
 	if (IS_ERR(hipcie->vpcie)) {
-		if (PTR_ERR(hipcie->vpcie) == -EPROBE_DEFER)
-			return -EPROBE_DEFER;
+		if (PTR_ERR(hipcie->vpcie) != -ENODEV)
+			return PTR_ERR(hipcie->vpcie);
 		hipcie->vpcie = NULL;
 	}
 
-- 
2.22.0