drm/tegra: sor: Fix AUX device reference leak

In the case where the AUX provides an I2C-over-AUX DDC channel, a
reference is taken on the AUX parent device of the DDC channel rather
than the DDC channel like it would be for regular I2C controllers. To
make sure the correct reference is dropped, move the unreferencing code
into the SOR driver and make sure not to drop the I2C adapter reference
in that case.

Signed-off-by: Thierry Reding <[email protected]>

Author: thierryreding

drivers/gpu/drm/tegra/output.c

@@ -180,13 +180,10 @@ int tegra_output_probe(struct tegra_output *output)
 
 void tegra_output_remove(struct tegra_output *output)
 {
-	int connector_type = output->connector.connector_type;
-
 	if (output->hpd_gpio)
 		free_irq(output->hpd_irq, output);
 
-	if (connector_type != DRM_MODE_CONNECTOR_eDP &&
-	    connector_type != DRM_MODE_CONNECTOR_DisplayPort && output->ddc)
+	if (output->ddc)
 		i2c_put_adapter(output->ddc);
 }
 

drivers/gpu/drm/tegra/sor.c

@@ -3745,12 +3745,8 @@ static int tegra_sor_probe(struct platform_device *pdev)
 		if (!sor->aux)
 			return -EPROBE_DEFER;
 
-		if (get_device(sor->aux->dev)) {
-			if (try_module_get(sor->aux->dev->driver->owner))
-				sor->output.ddc = &sor->aux->ddc;
-			else
-				put_device(sor->aux->dev);
-		}
+		if (get_device(sor->aux->dev))
+			sor->output.ddc = &sor->aux->ddc;
 	}
 
 	if (!sor->aux) {
@@ -3778,12 +3774,13 @@ static int tegra_sor_probe(struct platform_device *pdev)
 
 	err = tegra_sor_parse_dt(sor);
 	if (err < 0)
-		return err;
+		goto put_aux;
 
 	err = tegra_output_probe(&sor->output);
-	if (err < 0)
-		return dev_err_probe(&pdev->dev, err,
-				     "failed to probe output\n");
+	if (err < 0) {
+		dev_err_probe(&pdev->dev, err, "failed to probe output\n");
+		goto put_aux;
+	}
 
 	if (sor->ops && sor->ops->probe) {
 		err = sor->ops->probe(sor);
@@ -3970,7 +3967,14 @@ static int tegra_sor_probe(struct platform_device *pdev)
 	host1x_client_exit(&sor->client);
 	pm_runtime_disable(&pdev->dev);
 remove:
+	if (sor->aux)
+		sor->output.ddc = NULL;
+
 	tegra_output_remove(&sor->output);
+put_aux:
+	if (sor->aux)
+		put_device(sor->aux->dev);
+
 	return err;
 }
 
@@ -3988,6 +3992,11 @@ static int tegra_sor_remove(struct platform_device *pdev)
 
 	pm_runtime_disable(&pdev->dev);
 
+	if (sor->aux) {
+		put_device(sor->aux->dev);
+		sor->output.ddc = NULL;
+	}
+
 	tegra_output_remove(&sor->output);
 
 	return 0;