[PATCH] drm/tegra: Fix regulator_get_optional() misuse

[Mark Brown]

The tegra driver requests a supply using regulator_get_optional()
but both the name of the supply and the usage pattern suggest that it is
being used for the main power for the device and is not at all optional
for the device for function, there is no meaningful handling for absent
supplies.  Such regulators should use the vanilla regulator_get()
interface, it will ensure that even if a supply is not described in the
system integration one will be provided in software.

Signed-off-by: Mark Brown <broonie at kernel.org>
---
 drivers/gpu/drm/tegra/dpaux.c | 32 ++++++++++++--------------------
 1 file changed, 12 insertions(+), 20 deletions(-)

diff --git a/drivers/gpu/drm/tegra/dpaux.c b/drivers/gpu/drm/tegra/dpaux.c
index 622cdf1ad246..38686f56ea2f 100644
--- a/drivers/gpu/drm/tegra/dpaux.c
+++ b/drivers/gpu/drm/tegra/dpaux.c
@@ -505,18 +505,14 @@ static int tegra_dpaux_probe(struct platform_device *pdev)
 		return err;
 	}
 
-	dpaux->vdd = devm_regulator_get_optional(&pdev->dev, "vdd");
+	dpaux->vdd = devm_regulator_get(&pdev->dev, "vdd");
 	if (IS_ERR(dpaux->vdd)) {
-		if (PTR_ERR(dpaux->vdd) != -ENODEV) {
-			if (PTR_ERR(dpaux->vdd) != -EPROBE_DEFER)
-				dev_err(&pdev->dev,
-					"failed to get VDD supply: %ld\n",
-					PTR_ERR(dpaux->vdd));
-
-			return PTR_ERR(dpaux->vdd);
-		}
+		if (PTR_ERR(dpaux->vdd) != -EPROBE_DEFER)
+			dev_err(&pdev->dev,
+				"failed to get VDD supply: %ld\n",
+				PTR_ERR(dpaux->vdd));
 
-		dpaux->vdd = NULL;
+		return PTR_ERR(dpaux->vdd);
 	}
 
 	platform_set_drvdata(pdev, dpaux);
@@ -731,11 +727,9 @@ int drm_dp_aux_attach(struct drm_dp_aux *aux, struct tegra_output *output)
 	if (output->panel) {
 		enum drm_connector_status status;
 
-		if (dpaux->vdd) {
-			err = regulator_enable(dpaux->vdd);
-			if (err < 0)
-				return err;
-		}
+		err = regulator_enable(dpaux->vdd);
+		if (err < 0)
+			return err;
 
 		timeout = jiffies + msecs_to_jiffies(250);
 
@@ -767,11 +761,9 @@ int drm_dp_aux_detach(struct drm_dp_aux *aux)
 	if (dpaux->output->panel) {
 		enum drm_connector_status status;
 
-		if (dpaux->vdd) {
-			err = regulator_disable(dpaux->vdd);
-			if (err < 0)
-				return err;
-		}
+		err = regulator_disable(dpaux->vdd);
+		if (err < 0)
+			return err;
 
 		timeout = jiffies + msecs_to_jiffies(250);
 
-- 
2.20.1