media: staging: tegra-vde: Turn ON power domain on shutdown

On some devices bootloader isn't ready to a clamped VDE power, and thus,
machine hangs on a warm reboot (CPU reset). The VDE power partition is
turned ON by default on a cold boot, hence VDE driver should keep power
partition enabled on system's reboot too. This fixes hang on a warm reboot
on a Tegra20 Acer A500 device, which is handy if Embedded Controller
driver is unavailable, i.e. cold reboot can't be performed.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

diff --git a/drivers/staging/media/tegra-vde/vde.c b/drivers/staging/media/tegra-vde/vde.c
index 9dd9f0c..3dcf5ea 100644 (file)
--- a/drivers/staging/media/tegra-vde/vde.c
+++ b/drivers/staging/media/tegra-vde/vde.c
@@ -1081,9 +1081,17 @@ static int tegra_vde_remove(struct platform_device *pdev)
        struct tegra_vde *vde = platform_get_drvdata(pdev);
        struct device *dev = &pdev->dev;
 
+       pm_runtime_get_sync(dev);
        pm_runtime_dont_use_autosuspend(dev);
        pm_runtime_disable(dev);
 
+       /*
+        * Balance RPM state, the VDE power domain is left ON and hardware
+        * is clock-gated. It's safe to reboot machine now.
+        */
+       pm_runtime_put_noidle(dev);
+       clk_disable_unprepare(vde->clk);
+
        misc_deregister(&vde->miscdev);
 
        tegra_vde_dmabuf_cache_unmap_all(vde);
@@ -1095,6 +1103,16 @@ static int tegra_vde_remove(struct platform_device *pdev)
        return 0;
 }
 
+static void tegra_vde_shutdown(struct platform_device *pdev)
+{
+       /*
+        * On some devices bootloader isn't ready to a power-gated VDE on
+        * a warm-reboot, machine will hang in that case.
+        */
+       if (pm_runtime_status_suspended(&pdev->dev))
+               tegra_vde_runtime_resume(&pdev->dev);
+}
+
 static __maybe_unused int tegra_vde_pm_suspend(struct device *dev)
 {
        struct tegra_vde *vde = dev_get_drvdata(dev);
@@ -1140,6 +1158,7 @@ MODULE_DEVICE_TABLE(of, tegra_vde_of_match);
 static struct platform_driver tegra_vde_driver = {
        .probe          = tegra_vde_probe,
        .remove         = tegra_vde_remove,
+       .shutdown       = tegra_vde_shutdown,
        .driver         = {
                .name           = "tegra-vde",
                .of_match_table = tegra_vde_of_match,