[PATCH] drm/tegra: gr2d: fix autosuspend cleanup during teardown

[Guangshuo Li <lgs201920130244@gmail.com>]

gr2d_probe() calls pm_runtime_use_autosuspend(), but gr2d_remove()
does not call the matching pm_runtime_dont_use_autosuspend() during
teardown.

If the autosuspend delay is set to a negative value while autosuspend
is enabled, the runtime PM core increments usage_count to prevent
runtime suspend. Without calling pm_runtime_dont_use_autosuspend()
during teardown, this reference is not dropped.

The documentation for pm_runtime_use_autosuspend() also notes that it
is important to undo it with pm_runtime_dont_use_autosuspend() at
driver exit time, unless runtime PM was initially enabled with
devm_pm_runtime_enable().

Add the missing pm_runtime_dont_use_autosuspend() call to the driver
remove path.

This issue was found by manual code inspection.

Fixes: ace01e2af387 ("drm/tegra: gr2d/gr3d: Contain PM in the gr*d_probe/gr*d_remove")
Cc: stable@vger.kernel.org
Signed-off-by: Guangshuo Li <lgs201920130244@gmail.com>
---
 drivers/gpu/drm/tegra/gr2d.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/gpu/drm/tegra/gr2d.c b/drivers/gpu/drm/tegra/gr2d.c
index 892e3450b281..95e8a14a9648 100644
--- a/drivers/gpu/drm/tegra/gr2d.c
+++ b/drivers/gpu/drm/tegra/gr2d.c
@@ -296,6 +296,7 @@ static void gr2d_remove(struct platform_device *pdev)
 {
 	struct gr2d *gr2d = platform_get_drvdata(pdev);
 
+	pm_runtime_dont_use_autosuspend(&pdev->dev);
 	pm_runtime_disable(&pdev->dev);
 	host1x_client_unregister(&gr2d->client.base);
 }
-- 
2.43.0