diff options
| author | Thierry Reding <treding@nvidia.com> | 2019-12-02 17:29:03 +0300 |
|---|---|---|
| committer | Thierry Reding <treding@nvidia.com> | 2020-01-10 18:37:43 +0300 |
| commit | fd67e9c6ed5af223af0daee093593abe3dbb53d4 (patch) | |
| tree | b6fa196007ee3b62453fdb5481679ed18185023e /drivers/gpu/drm/tegra/drm.h | |
| parent | 608f43ad27ab26700677cc4d9ead3b2d9d338a21 (diff) | |
| download | linux-fd67e9c6ed5af223af0daee093593abe3dbb53d4.tar.xz | |
drm/tegra: Do not implement runtime PM
The Tegra DRM driver heavily relies on the implementations for runtime
suspend/resume to be called at specific times. Unfortunately, there are
some cases where that doesn't work. One example is if the user disables
runtime PM for a given subdevice. Another example is that the PM core
acquires a reference to runtime PM during system sleep, effectively
preventing devices from going into low power modes. This is intentional
to avoid nasty race conditions, but it also causes system sleep to not
function properly on all Tegra systems.
Fix this by not implementing runtime PM at all. Instead, a minimal,
reference-counted suspend/resume infrastructure is added to the host1x
bus. This has the benefit that it can be used regardless of the system
power state (or any transitions we might be in), or whether or not the
user allows runtime PM.
Atomic modesetting guarantees that these functions will end up being
called at the right point in time, so the pitfalls for the more generic
runtime PM do not apply here.
Signed-off-by: Thierry Reding <treding@nvidia.com>
Diffstat (limited to 'drivers/gpu/drm/tegra/drm.h')
| -rw-r--r-- | drivers/gpu/drm/tegra/drm.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/gpu/drm/tegra/drm.h b/drivers/gpu/drm/tegra/drm.h index d941553f7a3d..ed99b67deb29 100644 --- a/drivers/gpu/drm/tegra/drm.h +++ b/drivers/gpu/drm/tegra/drm.h @@ -144,6 +144,8 @@ int tegra_output_init(struct drm_device *drm, struct tegra_output *output); void tegra_output_exit(struct tegra_output *output); void tegra_output_find_possible_crtcs(struct tegra_output *output, struct drm_device *drm); +int tegra_output_suspend(struct tegra_output *output); +int tegra_output_resume(struct tegra_output *output); int tegra_output_connector_get_modes(struct drm_connector *connector); enum drm_connector_status |