drm/tegra: sor: Fully initialize SOR before registration

[ Upstream commit 5dea427 ]

Before registering the SOR host1x client, make sure that it is fully
initialized. This avoids a potential race condition between the SOR's
probe and the host1x device initialization in cases where the SOR is
the final sub-device to register to a host1x instance.

Reported-by: Jonathan Hunter <jonathanh@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Tested-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

drivers/gpu/drm/tegra/sor.c

@@ -3922,17 +3922,10 @@ static int tegra_sor_probe(struct platform_device *pdev)
 	platform_set_drvdata(pdev, sor);
 	pm_runtime_enable(&pdev->dev);
 
-	INIT_LIST_HEAD(&sor->client.list);
+	host1x_client_init(&sor->client);
 	sor->client.ops = &sor_client_ops;
 	sor->client.dev = &pdev->dev;
 
-	err = host1x_client_register(&sor->client);
-	if (err < 0) {
-		dev_err(&pdev->dev, "failed to register host1x client: %d\n",
-			err);
-		goto rpm_disable;
-	}
-
 	/*
 	 * On Tegra210 and earlier, provide our own implementation for the
 	 * pad output clock.
@@ -3944,13 +3937,13 @@ static int tegra_sor_probe(struct platform_device *pdev)
 				      sor->index);
 		if (!name) {
 			err = -ENOMEM;
-			goto unregister;
+			goto uninit;
 		}
 
 		err = host1x_client_resume(&sor->client);
 		if (err < 0) {
 			dev_err(sor->dev, "failed to resume: %d\n", err);
-			goto unregister;
+			goto uninit;
 		}
 
 		sor->clk_pad = tegra_clk_sor_pad_register(sor, name);
@@ -3961,14 +3954,20 @@ static int tegra_sor_probe(struct platform_device *pdev)
 		err = PTR_ERR(sor->clk_pad);
 		dev_err(sor->dev, "failed to register SOR pad clock: %d\n",
 			err);
-		goto unregister;
+		goto uninit;
+	}
+
+	err = __host1x_client_register(&sor->client);
+	if (err < 0) {
+		dev_err(&pdev->dev, "failed to register host1x client: %d\n",
+			err);
+		goto uninit;
 	}
 
 	return 0;
 
-unregister:
-	host1x_client_unregister(&sor->client);
-rpm_disable:
+uninit:
+	host1x_client_exit(&sor->client);
 	pm_runtime_disable(&pdev->dev);
 remove:
 	tegra_output_remove(&sor->output);