drm/tegra: Enable runtime PM during probe

Currently, engine drivers only enable runtime PM during the host1x
init callback. This can happen slightly later than the probe, which
can cause the power domain to intermittently not be turned off after
probe.

My hypothesis is that there is a race condition between the post-probe
power domain poweroff that is done from a queued work, and the
pm_runtime_enable call happening in the host1x init callback.
If the pm_runtime_enable call happens first, everything is OK and
the power off work can disable the power domain as PM runtime is
enabled and the device is runtime suspended. If power off work runs
first, PM runtime is still disabled for the device and the domain
must be kept powered.

Resolve the issue by moving the runtime PM enablement to the
probe function.
Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230613095215.2497004-1-cyndis@kapsi.fi

drivers/gpu/drm/tegra/gr2d.c

@@ -71,22 +71,15 @@ static int gr2d_init(struct host1x_client *client)
 		goto free;
 	}
 
-	pm_runtime_enable(client->dev);
-	pm_runtime_use_autosuspend(client->dev);
-	pm_runtime_set_autosuspend_delay(client->dev, 200);
-
 	err = tegra_drm_register_client(dev->dev_private, drm);
 	if (err < 0) {
 		dev_err(client->dev, "failed to register client: %d\n", err);
-		goto disable_rpm;
+		goto detach_iommu;
 	}
 
 	return 0;
 
-disable_rpm:
-	pm_runtime_dont_use_autosuspend(client->dev);
-	pm_runtime_force_suspend(client->dev);
-
+detach_iommu:
 	host1x_client_iommu_detach(client);
 free:
 	host1x_syncpt_put(client->syncpts[0]);
@@ -300,6 +293,7 @@ static void gr2d_remove(struct platform_device *pdev)
 {
 	struct gr2d *gr2d = platform_get_drvdata(pdev);
 
+	pm_runtime_disable(&pdev->dev);
 	host1x_client_unregister(&gr2d->client.base);
 }
 
@@ -373,6 +367,10 @@ static int __maybe_unused gr2d_runtime_resume(struct device *dev)
 		goto disable_clk;
 	}
 
+	pm_runtime_enable(dev);
+	pm_runtime_use_autosuspend(dev);
+	pm_runtime_set_autosuspend_delay(dev, 500);
+
 	return 0;
 
 disable_clk:

drivers/gpu/drm/tegra/gr3d.c

@@ -80,22 +80,15 @@ static int gr3d_init(struct host1x_client *client)
 		goto free;
 	}
 
-	pm_runtime_enable(client->dev);
-	pm_runtime_use_autosuspend(client->dev);
-	pm_runtime_set_autosuspend_delay(client->dev, 200);
-
 	err = tegra_drm_register_client(dev->dev_private, drm);
 	if (err < 0) {
 		dev_err(client->dev, "failed to register client: %d\n", err);
-		goto disable_rpm;
+		goto detach_iommu;
 	}
 
 	return 0;
 
-disable_rpm:
-	pm_runtime_dont_use_autosuspend(client->dev);
-	pm_runtime_force_suspend(client->dev);
-
+detach_iommu:
 	host1x_client_iommu_detach(client);
 free:
 	host1x_syncpt_put(client->syncpts[0]);
@@ -554,6 +547,7 @@ static void gr3d_remove(struct platform_device *pdev)
 {
 	struct gr3d *gr3d = platform_get_drvdata(pdev);
 
+	pm_runtime_disable(&pdev->dev);
 	host1x_client_unregister(&gr3d->client.base);
 }
 
@@ -607,6 +601,10 @@ static int __maybe_unused gr3d_runtime_resume(struct device *dev)
 		goto disable_clk;
 	}
 
+	pm_runtime_enable(dev);
+	pm_runtime_use_autosuspend(dev);
+	pm_runtime_set_autosuspend_delay(dev, 500);
+
 	return 0;
 
 disable_clk:

drivers/gpu/drm/tegra/nvdec.c

@@ -175,13 +175,9 @@ static int nvdec_init(struct host1x_client *client)
 		goto free_channel;
 	}
 
-	pm_runtime_enable(client->dev);
-	pm_runtime_use_autosuspend(client->dev);
-	pm_runtime_set_autosuspend_delay(client->dev, 500);
-
 	err = tegra_drm_register_client(tegra, drm);
 	if (err < 0)
-		goto disable_rpm;
+		goto free_syncpt;
 
 	/*
 	 * Inherit the DMA parameters (such as maximum segment size) from the
@@ -191,10 +187,7 @@ static int nvdec_init(struct host1x_client *client)
 
 	return 0;
 
-disable_rpm:
-	pm_runtime_dont_use_autosuspend(client->dev);
-	pm_runtime_force_suspend(client->dev);
-
+free_syncpt:
 	host1x_syncpt_put(client->syncpts[0]);
 free_channel:
 	host1x_channel_put(nvdec->channel);
@@ -539,6 +532,10 @@ static int nvdec_probe(struct platform_device *pdev)
 		goto exit_falcon;
 	}
 
+	pm_runtime_enable(dev);
+	pm_runtime_use_autosuspend(dev);
+	pm_runtime_set_autosuspend_delay(dev, 500);
+
 	return 0;
 
 exit_falcon:
@@ -551,8 +548,8 @@ static void nvdec_remove(struct platform_device *pdev)
 {
 	struct nvdec *nvdec = platform_get_drvdata(pdev);
 
+	pm_runtime_disable(&pdev->dev);
 	host1x_client_unregister(&nvdec->client.base);
-
 	falcon_exit(&nvdec->falcon);
 }
 

drivers/gpu/drm/tegra/vic.c

@@ -141,13 +141,9 @@ static int vic_init(struct host1x_client *client)
 		goto free_channel;
 	}
 
-	pm_runtime_enable(client->dev);
-	pm_runtime_use_autosuspend(client->dev);
-	pm_runtime_set_autosuspend_delay(client->dev, 500);
-
 	err = tegra_drm_register_client(tegra, drm);
 	if (err < 0)
-		goto disable_rpm;
+		goto free_syncpt;
 
 	/*
 	 * Inherit the DMA parameters (such as maximum segment size) from the
@@ -157,10 +153,7 @@ static int vic_init(struct host1x_client *client)
 
 	return 0;
 
-disable_rpm:
-	pm_runtime_dont_use_autosuspend(client->dev);
-	pm_runtime_force_suspend(client->dev);
-
+free_syncpt:
 	host1x_syncpt_put(client->syncpts[0]);
 free_channel:
 	host1x_channel_put(vic->channel);
@@ -527,6 +520,10 @@ static int vic_probe(struct platform_device *pdev)
 		goto exit_falcon;
 	}
 
+	pm_runtime_enable(dev);
+	pm_runtime_use_autosuspend(dev);
+	pm_runtime_set_autosuspend_delay(dev, 500);
+
 	return 0;
 
 exit_falcon:
@@ -539,8 +536,8 @@ static void vic_remove(struct platform_device *pdev)
 {
 	struct vic *vic = platform_get_drvdata(pdev);
 
+	pm_runtime_disable(&pdev->dev);
 	host1x_client_unregister(&vic->client.base);
-
 	falcon_exit(&vic->falcon);
 }