[PATCH 2/5] PCI: imx6: 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: Richard Zhu <hongxing.zhu@nxp.com>
Cc: Lucas Stach <l.stach@pengutronix.de>
Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Fabio Estevam <festevam@gmail.com>
Cc: kernel@pengutronix.de
Cc: linux-imx@nxp.com
Signed-off-by: Thierry Reding <treding@nvidia.com>
---
 drivers/pci/controller/dwc/pci-imx6.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
index 8b8efa3063f5..acfbd34032a8 100644
--- a/drivers/pci/controller/dwc/pci-imx6.c
+++ b/drivers/pci/controller/dwc/pci-imx6.c
@@ -1174,8 +1174,8 @@ static int imx6_pcie_probe(struct platform_device *pdev)
 
 	imx6_pcie->vpcie = devm_regulator_get_optional(&pdev->dev, "vpcie");
 	if (IS_ERR(imx6_pcie->vpcie)) {
-		if (PTR_ERR(imx6_pcie->vpcie) == -EPROBE_DEFER)
-			return -EPROBE_DEFER;
+		if (PTR_ERR(imx6_pcie->vpcie) != -ENODEV)
+			return PTR_ERR(imx6_pcie->vpcie);
 		imx6_pcie->vpcie = NULL;
 	}
 
-- 
2.22.0